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A050913 Pure 2-complexes on an infinite set of nodes with n multiple 2-simplexes. Also n-rowed binary matrices with all row sums 3, up to row and column permutation. 15
1, 1, 4, 16, 93, 652, 6369, 79568, 1256425, 24058631, 543204998, 14138916124, 417362929209, 13798729189578, 505990335048034, 20415765544541866, 900364519682003919, 43155049922002494115, 2236988329443856718604, 124862936181977439454012, 7476052709321753156375756, 478506183522725779096476581, 32638841238874891261354722405, 2365895836144423508306322639848, 181785988254681334224483607437510, 14771116583797935886529061991645404, 1266545494725474774697216198539818982 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..26.

Vladeta Jovovic, Number of m-rowed binary matrices with all row sums equal to n, up to row and column permutation

CROSSREFS

Row n=3 of A331461.

Cf. A050911, A050912, A001400, A014395, A082789, A082790, A058790.

Sequence in context: A003762 A143501 A111291 * A096243 A263565 A131928

Adjacent sequences:  A050910 A050911 A050912 * A050914 A050915 A050916

KEYWORD

nonn

AUTHOR

Vladeta Jovovic, Dec 29 1999

EXTENSIONS

More terms from T. Forbes (anthony.d.forbes(AT)googlemail.com), May 24, 2003

STATUS

approved

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Last modified March 1 14:42 EST 2021. Contains 341736 sequences. (Running on oeis4.)