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A305027
Array read by antidiagonals: T(n,m) is the number of nonisomorphic binary n X m matrices with 3 1's per column under row and column permutations (m >= 3).
4
1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 3, 1, 1, 1, 4, 7, 5, 1, 1, 1, 4, 11, 17, 6, 1, 1, 1, 4, 14, 40, 35, 9, 1, 1, 1, 4, 15, 62, 122, 76, 11, 1, 1, 1, 4, 16, 78, 272, 410, 149, 15, 1, 1, 1, 4, 16, 87, 427, 1307, 1270, 291, 18, 1, 1, 1, 4, 16, 91, 544, 2754, 6178, 3888, 539, 23, 1
OFFSET
0,9
COMMENTS
Also, the number of pure 2-complexes on m nodes with n multiple 2-simplexes.
EXAMPLE
Array begins:
========================================================
n\m| 3 4 5 6 7 8 9 10 11
---+----------------------------------------------------
0 | 1 1 1 1 1 1 1 1 1 ...
1 | 1 1 1 1 1 1 1 1 1 ...
2 | 1 2 3 4 4 4 4 4 4 ...
3 | 1 3 7 11 14 15 16 16 16 ...
4 | 1 5 17 40 62 78 87 91 92 ...
5 | 1 6 35 122 272 427 544 606 635 ...
6 | 1 9 76 410 1307 2754 4251 5343 5939 ...
7 | 1 11 149 1270 6178 18247 36455 54621 67609 ...
8 | 1 15 291 3888 28687 122038 327774 616020 891831 ...
...
PROG
(PARI) \\ See A304942 for Blocks
for(n=1, 8, for(m=3, 11, print1(Blocks(n, m, 3), ", ")); print)
CROSSREFS
Columns m=4..7 are A001400, A014395, A050911, A050912.
A diagonal is A247596.
Cf. A050913 (infinite m), A304942.
Sequence in context: A099233 A303912 A133815 * A335570 A362644 A323718
KEYWORD
nonn,tabl
AUTHOR
Andrew Howroyd, May 24 2018
STATUS
approved