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A247596
Number of nonisomorphic binary n X n matrices with three 1's per column under row and column permutations.
6
1, 5, 35, 410, 6178, 122038, 2921607, 81609320, 2588949454, 91699869557, 3582942335285, 153048366545566, 7096576775166579, 355120233277118103, 19084972486216897560, 1096965038775477639368, 67192642484367187943761, 4372413334294007638726854
OFFSET
3,2
MAPLE
seq(matrix_marks(n, 3), n=3..15); # Using the uploaded program to A247417
PROG
(PARI) \\ See A304942 for Blocks
a(n) = Blocks(n, n, 3); \\ Andrew Howroyd, May 23 2018
CROSSREFS
Column k=3 of A304942.
A diagonal of A305027.
Sequence in context: A204290 A059865 A376322 * A325408 A097492 A125802
KEYWORD
nonn
AUTHOR
Marko Riedel, Sep 21 2014
EXTENSIONS
Terms a(17) and beyond from Andrew Howroyd, May 23 2018
STATUS
approved