Small NBIBDs with r≥(v-1).

Round brackets () are used for blocks, [] is used for resolution classes, [[]] is used for 2-resolution classes, etc. Vertical bars | separate sub-blocks. Some of the designs here are of a more general type (Type II as opposed to Type I), in which corresponding individual sub-blocks within the main blocks constitute sub-designs (see the definitions). The sub-designs are demarcated by double vertical bars, thus ||.

Most of the the designs (the numbered ones) may be found in a more detailed collection in Morgan, Preece & Rees; No 39 is due to Deng, Greig & Östergård. Various (un-numbered) designs have been added at the end for use elsewhere: these are for non-primes only. The designs for v=18 are due to Sreenath. The designs for v=24 are derived from an OBIBD published in Abel,Greig & Rees, those for v=27 from an OBIBD here, while those for 30 and 36 are GWhDs published by Abel, Finizio & Greig. Designs for 28 and 40 may be derived from PMDs published by Abel, Bennett & Zhang, but are too complex to be included here (in the presented form).

If a design is known to exist for a particular set of parameters, no multiple of that parameter set is included in the table.

No vb1b2rk1k2Blocks
15510442(1 4 | 2 3) mod 5
27721662(1 3 | 2 6 | 4 5) mod 7
37714663(1 2 4 || 6 5 3) mod 7
481428742[(0 1 | 4 2) (3 6 | 5 ∞ )] mod 7
591836842(01 02 | 10 20) (11 22 | 12 21) mod(3,3)
691236862 [[(1 2 | 3 6 | 4 ∞ ) (5 6 | 7 2 | 0 ∞ )(0 4 | 1 7 | 3 5 )]] PC(4) mod 8
791224863 [[(1 3 4 || 2 6 ∞ ) (2 6 ∞ || 5 7 0) (5 7 0 || 1 3 4)]] PC(4) mod 8
89936882(01 02 | 10 20 | 11 22 | 12 21) mod(3,3)
99918884(01 02 10 20 | 11 22 12 21) mod(3,3)
10101545962 (00 20 | 30 21 | 31 41) (20 30 | 00 31 | 40 01) (00 01 | 10 31 | 21 41) mod 5 (suffixes fixed)
11101530963No NBIBD exists, but a double (No 47) and a triple (No 58) exist.
12101030993 (10 20 41 | 30 40 31 | 01 11 21) (20 31 00 | 10 21 30 | 11 40 41) mod 5 (suffixes fixed)
13615301042 [(1 5 || 1 3) (4 0 || 5 2) (3 1 || 4 0)]] PC(3) [[(1 2 || 3 4) (3 4 || 5 0) (5 0 || 1 2)]] PC(2) both mod 6
1411115510102(1 10 | 2 9 | 3 8 | 4 7 | 5 6) mod 11
1511112210105(1 3 4 5 9 || 2 6 8 10 7) mod 11
161233661142[(0 1 | 3 7) (10 2 | 9 4) (8 6 | 5 ∞ )] mod 11
171222661162[(0 3 | 1 5 | 4 9) (8 10 | 7 6 | 2 ∞ )] mod 11
181222441163[(0 1 3 | 4 5 9) (10 7 ∞ | 6 8 2)] mod 11
19721421242(0 1 || 4 2) (0 2 || 1 4) (0 4 || 2 1) mod 7
201339781242(1 12 | 5 8) (2 11 | 3 10) (4 9 | 6 7) mod 13
211326781262(3 10 | 4 9 | 1 12) (5 8 | 11 2 | 6 7) mod 13
221326521263(1 3 9 || 4 12 10) (2 6 5 || 7 8 11) mod 13
2313137812122(1 12 | 2 11 | 3 10 | 4 9 | 5 8 | 6 7) mod 13
2413135212123(1 3 9 | 2 6 5 || 4 12 10 | 7 8 11) mod 13
2513133912124(1 12 5 8 | 2 11 3 10 | 4 9 6 7) mod 13
2613132612126(1 3 9 4 12 10 | 2 6 5 7 8 11) mod 13
2715351051462 (11 00 | 21 01 | 41 ∞ ) (00 30 | 01 50 | ∞ 60)
(20 10 | 40 31 | 11 01) (20 01 | 50 11 | 31 30)
(40 11 | 50 00 | 01 31) mod 7 (suffixes fixed)
281535701463 (11 21 41 || 00 01 ∞ ) (00 01 ∞ || 30 50 60)
(20 40 11 || 10 31 01) (20 50 31 || 01 11 30)
(40 50 01 || 11 00 31) mod 7 (suffixes fixed)
29152110514102No D1 exists, so no NBIBD exists, but a double exists (No 60).
3015214214105No D1 exists, so no NBIBD exists, but a double exists (No 61).
3115151051414 2 (1 14 | 2 13 | 3 12 | 4 11 | 5 10 | 6 9 | 7 8) mod 15
3215153014147 (I 40 10 11 20 41 21 | 01 61 51 50 31 60 30)
(00 20 40 51 10 61 31 | ∞ 60 50 41 30 21 11)
mod 7 (suffixes fixed) with
(01 11 21 31 41 51 61 | 00 10 20 30 40 50 60)
3316601201542 [(I 0 | 5 10)(1 2 | 4 8)(6 9 | 7 13)(11 3 | 12 14)] mod 15
3416401201562 (0 1 | 9 3 | 5 12) (0 3 | 1 12 | 6 2)
(11 9 | 1 3 | 0 8) PC(8) mod 16
351640801563 (01 02 03 | 12 22 32) (I 31 41 | 01 32 43)
(11 31 03 | 13 02 22) (I 22 43 | 01 32 13)
(11 31 02 | 01 33 42) (I 32 13 | 01 12 33)
(21 31 42 | 41 03 13) (01 02 03 | 13 23 43)
mod 5 with indices fixed
3616301201582 [(I 0 | 3 14 | 1 4 | 9 7)(2 8 | 6 13 | 5 10 | 11 12)] mod 15
371630601584[(0 1 3 7 | 4 9 14 ∞ ) (2 10 11 13 | 5 6 8 12)] mod 15
38162412015102 (I1 01 | ∞ 2 02 | 12 13 | 22 24 | 23 14)
(I2 03 | ∞ 3 02 | 11 24 | 21 23 | 13 14)
(I1 03 | ∞ 3 01 | 11 22 | 21 14 | 12 24)
(I2 24 | ∞ 3 23 | ∞ 4 02 | 01 22 | 11 12)
(I1 02 | ∞ 3 24 | ∞ 4 03 | 21 13 | 12 23)
(I1 24 | ∞ 2 11 | ∞ 4 01 | 21 03 | 22 13)
(I4 04 | 11 21 | 12 22 | 13 23 | 14 24)
mod 3 with
v (I12 | ∞ 34 | 21 24 | 22 14 | 23 04)
(I13 | ∞ 24 | 01 04 | 02 24 | 03 14)
(I14 | ∞ 23 | 11 14 | 12 04 | 13 24)
3916244815105 (0,1,2,3,4 | 5,6,7,8,9)(0,1,2,3,5 | 4,6,10,11,12)
(0,1,2,3,6 | 4,5,13,14,15)(0,1,10,11,12 | 2,3,7,8,9)
(0,2,13,14,15 | 1,3,7,8,9)(0,3,13,14,15 | 1,2,10,11,12)
(0,4,5,7,11 | 1,8,10,13,14)(0,4,5,9,10 | 1,7,12,13,15)
(0,4,5,8,12 | 1,9,11,14,15)(0,6,7,10,13 | 2,4,8,11,14)
(0,6,9,12,15 | 2,4,7,10,13) (0,6,8,11,14 | 2,4,9,12,15)
(0,7,8,10,15 | 3,5,6,12,14) (0,7,9,12,14 | 3,5,6,11,13)
(0,8,9,11,13 | 3,5,6,10,15) (1,5,7,12,14 | 2,6,8,10,15)
(1,5,9,11,13 | 2,6,7,12,14) (1,5,8,9,15 | 2,6,9,11,13)
(1,4,6,7,13 | 3,8,11,12,15) (1,4,6,9,15 | 3,7,10,11,14)
(1,4,6,8,14 | 3,4,8,12,13) (2,5,7,11,15 | 3,4,8,12,13)
(2,5,9,10,14 | 3,4,7,11,15) (2,5,8,12,13 | 3,4,9,10,14)
40162012015122 [[[(1 2 | 4 8 | 6 13 | 7 9 | 0 5 | 10 ∞ )
(6 7 | 9 13 | 11 3 | 12 14 | 5 10 | 0 ∞ )
(11 12 | 14 3 | 1 8 | 2 4 | 10 0 | 5 ∞ )
(1 4 | 6 9 | 11 14 | 2 8 | 7 13 | 12 3)]]]
PC(5) mod 15
4116208015123 [[[(0 1 5 | 2 8 10 | 6 7 9 | 13 4 ∞ )
(5 6 10 | 7 13 0 | 11 12 14 | 3 9 ∞ )
(10 11 0 | 12 3 5 | 1 2 4 | 8 14 ∞ )
(2 7 12 | 1 4 8 | 6 9 13 | 3 11 14) ]]]
PC(5) mod 15
4216206015124 [[[(1 2 4 8 || 6 7 9 13 || 0 5 10 ∞ )
(6 7 9 13 || 5 10 0 ∞ || 11 12 14 3)
( 10 0 5 ∞ || 11 12 14 3 || 1 2 4 8)
(11 12 14 3 || 1 2 4 8 || 6 7 9 13)]]]
PC(5) mod 15
4316204015126 [[[(0 5 1 4 7 13 | 2 6 8 10 9 ∞ )
(5 10 6 9 12 3 | 7 11 13 0 14 ∞ )
(10 0 11 14 2 8 | 12 1 3 5 4 ∞ )
(1 9 6 14 11 4 | 8 7 13 12 3 2)]]]
PC(5) mod 15
4416168015153 (0001 0110 0111 | 0010 1100 1110 | 0100 1011 1111 |1000 0101 1101 | 0011 1010 1001) mod(2,2,2,2)
4516164815155 (0001 1000 1100 1010 1111 | 0010 0011 1011 0111 1101 | 0100 0110 0101 1110 1001)
mod(2,2,2,2)
461045901842 (1 2 | 3 5) (1 4 | 3 7) (0 2 | 4 5) (0 3 | 1 6) mod 10
with (1 7 | 2 6) PC(5)
471030601863 (1 2 4 | 5 6 9) (1 2 7 | 3 5 8) (1 2 4 | 3 5 9)
mod 10
481326781893 (2 6 5 || 4 12 10 || 8 11 7)
(1 3 9 || 8 11 7 || 4 12 10) mod 13
4911551102042 (10 9 || 1 2) (9 7 || 2 4) (7 3 || 4 8) (3 6 || 8 5)
(6 1 || 5 10) mod 11
50828842162 [[[(1 3 || 2 6 || 4 5) (I 0 || 4 5 || 2 6)
(4 5 || ∞ 0 || 1 3) (2 6 || 1 3 || ∞ 0)]]] mod 7
51828562163 [[[(1 2 4 | 3 6 5) (I 4 2 | 0 5 6)
(4 ∞ 1 | 5 0 3) (2 1 ∞ | 6 3 0)]]] mod 7
5215351052193 (01 41 52 | 11 31 42 | 21 51 22)
(01 11 31 | 02 12 32 | 22 42 52 )
(01 22 32 | 21 31 12 | 41 62 ∞ )
(11 12 42 | 21 31 02 | 61 62 ∞ )
(01 21 12 | 11 32 52 | 51 42 ∞ )
mod 7
5312331322282 [[(2 10 | 4 9 | 6 8 | 5 ∞ )
(0 1 | 3 7 | 6 8 | 5 ∞ ) (0 1 | 3 7 | 2 10 | 4 9)]]
mod 11
541233662284 [[( 2 10 4 9 | 6 8 5 ∞ )( 0 1 3 7 | 6 8 5 ∞ )
( 0 1 3 7 | 2 10 4 9) ]] mod 11
5513391562482 (1 12 | 5 8 | 2 11 | 3 10) (4 9 | 6 7 | 1 12 | 5 8)
(2 11 | 3 10 | 4 9 | 6 7) mod 13
561339782484 (1 12 5 8 || 2 11 3 10) (4 9 6 7 || 1 12 5 8)
(2 11 3 10 || 4 9 6 7) mod 13
5714911822642 (0 1 || 9 8) (0 2 || 5 3) (0 8 || 1 9) (0 3 || 2 5)
(0 4 || 7 11) (I 0 || 2 9) (3 9 || ∞ 0) mod 13
581045902763 (2 3 4 | 1 6 ∞ ) (1 2 5 | 3 6 ∞ ) ( 1 3 5 | 2 8 ∞ )
(1 3 5 | 2 8 7) (1 2 7 | 3 4 6) mod 9
59151052102842 (1 6 || 3 10) (1 13 || 2 8) (1 2 || 6 8) (7 14 || 1 2 )
(2 8 || 1 4 ) (2 4 || 1 12) (1 5 || 2 7) mod 15
60154221028102 (0 2 | 3 11 | 4 13 | 5 12 | 6 9) (0 1 | 2 5 | 3 13 | 4 10 | 9 ∞ )
(0 1 | 3 5 | 7 11 | 8 13 | 10 ∞ ) mod 14
6115428428105 (0 7 8 9 11 | 2 3 4 5 10) (0 5 6 9 10 | 1 4 7 8 ∞ )
(0 2 5 7 11 | 4 8 10 12 ∞ ) mod 14
62153521028122 [[[[(12 02 | 62 52 | 32 31 | 42 ∞ | 01 51 | 21 41)
(52 02 | 41 11 | 61 22 | 12 01 | 62 ∞ | 31 32)
(11 ∞ | 61 42 | 21 52 | 02 32 | 62 51 | 22 01)
(01 11 | 02 51 | 21 ∞ | 42 61 | 12 41 | 22 31)
(52 32 | 31 61 | 12 41 | 42 51 | 22 62 | 11 21)]]]]
mod 7 (suffixes fixed)
63153514028123 (0 3 14 || 7 8 11 || 9 10 13 || 4 6 12 )
(0 2 8 || 4 11 13 || 5 12 14 || 6 7 10 )
(1 6 11 || 2 7 12 || 3 8 13 || 4 9 14 )
mod 15, last block PC(5)
64153510528124 [[[[(12 02 62 52 | 32 31 42 ∞ | 01 51 21 41)
(52 02 41 11 | 61 22 12 01 | 62 ∞ 31 32)
(11 ∞ 61 42 | 21 52 02 32 | 62 51 22 01)
(01 11 02 51 | 21 ∞ 42 61 | 12 41 22 31)
(52 32 31 61 | 12 41 42 51 | 22 62 11 21)]]]]
mod 7 (suffixes fixed)
6515357028126 (01 02 ∞ 21 51 42 | 32 52 62 41 31 12)
(11 61 22 41 31 12 | 01 02 ∞ 32 52 62)
(21 51 42 32 52 62 | 11 61 22 01 02 ∞ )
(41 31 12 01 02 ∞ | 21 51 42 11 61 22)
(32 52 62 11 61 22 | 41 31 12 21 51 42)
mod 7 (suffixes fixed)
6611551653062 (0 2 || 8 7 || 10 6) (0 8 || 10 6 || 7 2)
(0 10 || 7 2 || 6 8) (0 7 || 6 8 || 2 10)
(0 6 || 2 10 || 8 7) mod 11
6711551103063 (10 4 6 || 1 7 5) (4 6 9 || 7 5 2) (6 9 8 || 5 2 3)
(9 8 1 || 2 3 10) (8 1 7 || 3 10 4) mod 11
6816801603063 (1111 0100 1011 | 0011 1010 1001)
(0011 1010 1001 | 1110 0010 1100)
(1110 0010 1100 | 1000 0101 1101)
(1000 0101 1101 | 0111 0001 0110)
(0111 0001 0110 | 0100 1011 1111
mod (2,2,2,2)
6916489630105 (1101 0011 0111 0010 1011 | 0110 1110 0100 0101 1001)
(0110 1110 0100 0101 1001 | 1111 1000 1010 0001 1100)
(1111 1000 1010 0001 1100 | 0011 0111 0010 1011 1101)
mod (2,2,2,2)
 18511531762 (∞,2 | 0,8 | 12,9) (0,7 | 1,3 | 8,12)
(0,1 | 2,7 | 15,4) mod 17
 18511021763 (∞, 0, 12 | 2, 8, 9) (0, 1, 8 | 7, 3, 12)
(0, 2, 15 | 1, 7, 4) mod 17
 21702102062 (20, 1 | 0, 3 | 5, 7) (0, 7 | 1, 9 | 4, 15)
(0, 5 | 1, 15 | 8, 12) (0, 1 | 2, 12 | 10, 11)
mod 20, last block PC(10)
 21701402063 (20, 5, 7 | 0, 1, 3) (0, 4, 7 | 1, 9, 15)
(0, 5, 15 | 1, 8, 12) (0, 1, 12 | 2, 10, 11)
mod 20, last block PC(10)
 22772312162 (0, 1 | 2, 5 | 8, 17) (0, 16 | 1, 5 | 3, 8)
(0, 14 | 2, 9 | 6, 18) (0, 2 | 1, 12 | 11, 13)
mod 22, last block PC(11)
 24922762362 (0,11 | 1,8 | 13,17) (0,10 | 2,22 | 17,3)
(0,6 | 15,13 | 10,11) (0,5 | 22,14 | 3,∞) mod 23
 24921842363 (0,1,13 | 11,8,17 ) (0,2,17 | 10,22,3 )
(0,15,10 | 6,13,11 ) (0,22,3 | 5,14,∞ ) mod 23
 271173512662 [[(∞,1 | 0,9 | 13,3 )(1,14 | 9,16 | 3,22)
(14,∞ | 16,0 | 22,13) (2,10 | 21, 6 | 12,11 )
(10,4 | 6,18 | 11,7 ) (4,2 | 18,21 | 7,12)
(15,17 | 15,20 | 8,5 ) (17,23 | 20,24 | 5,19 )
(23,15 | 24,25 | 19,8)]] mod 26, in steps of 2
 271172342663 [[(∞,0,13 || 1,9,3 )(1,9,3 || 14, 16, 22)
(14,16,22 || ∞,0,13)(2,21,12 || 10, 6, 11)
(10,6,11 || 4,18,7) (4,18,7 | 2,21,12)
(15,25,8 || 17, 20, 5) (17,20,5 || 23,24,19)
(23,24,19 || 15,25,8)]] mod 26, in steps of 2
 301454352962 (∞,0 | 26,3 | 27,14) (28,25 | 7,16 | 9,24) (2,4 | 6,17 | 10,22) (11,21 | 1,23 | 15,20) (8,12 | 5,13 | 18,19) mod 29
 301452902963 [(∞,0,7 | 18,20,26) (11,15,17 | 5,16,3) (14,4,1 | 10,21,25) (28,8,9 | 6,22,23) (19,24,2 | 12,3,7)] mod 29
 362106303562 (∞,0 | 16,25 | 34,2) (23,6 | 22,12 | 8,29) (27,28 | 3,33 | 14,20) (7,26 | 30,10 | 15,17) (5,1 | 4,31 | 19,32) (9,21 | 13,24 | 11,18) mod 35
 362104203563 [(∞,0,33 | 14,23,32) (1,25,26 | 12,18,31) (6,20,21 | 4,10,27) (7,11,22 | 9,16,19) (2,29,34 | 3,17,30) (5,24,28 | 8,13,15)] mod 35

Last Updated: 23rd May 2005