cp's OEIS Frontend

A188408 Number of (7*n) X n binary arrays with rows in nonincreasing order, 7 ones in every column and no more than 2 ones in any row.

%I A188408 #11 Apr 07 2020 15:29:27
%S A188408 1,1,8,154,7340,681460,111200600,29445929253,11930327925108,
%T A188408 7061916086148812,5884543061841730064,6695191219474600587460,
%U A188408 10138670050730337096234992,19996250425584243540741431296,50416254105984511132422687541856,159887463958073530310081258765881180
%N A188408 Number of (7*n) X n binary arrays with rows in nonincreasing order, 7 ones in every column and no more than 2 ones in any row.
%C A188408 Number of n X n symmetric matrices with nonnegative integer entries and all row and column sums 7. - _Andrew Howroyd_, Apr 07 2020
%e A188408 All solutions for 14X2
%e A188408 ..1..1....1..1....1..1....1..1....1..1....1..1....1..0....1..1
%e A188408 ..1..1....1..1....1..1....1..1....1..1....1..0....1..0....1..1
%e A188408 ..1..0....1..1....1..1....1..1....1..1....1..0....1..0....1..1
%e A188408 ..1..0....1..1....1..1....1..1....1..1....1..0....1..0....1..0
%e A188408 ..1..0....1..0....1..1....1..1....1..1....1..0....1..0....1..0
%e A188408 ..1..0....1..0....1..1....1..0....1..1....1..0....1..0....1..0
%e A188408 ..1..0....1..0....1..0....1..0....1..1....1..0....1..0....1..0
%e A188408 ..0..1....0..1....0..1....0..1....0..0....0..1....0..1....0..1
%e A188408 ..0..1....0..1....0..0....0..1....0..0....0..1....0..1....0..1
%e A188408 ..0..1....0..1....0..0....0..0....0..0....0..1....0..1....0..1
%e A188408 ..0..1....0..0....0..0....0..0....0..0....0..1....0..1....0..1
%e A188408 ..0..1....0..0....0..0....0..0....0..0....0..1....0..1....0..0
%e A188408 ..0..0....0..0....0..0....0..0....0..0....0..1....0..1....0..0
%e A188408 ..0..0....0..0....0..0....0..0....0..0....0..0....0..1....0..0
%Y A188408 Row 7 of A188403.
%K A188408 nonn
%O A188408 0,3
%A A188408 _R. H. Hardin_, Mar 30 2011
%E A188408 a(0)=1 prepended and terms a(9) and beyond from _Andrew Howroyd_, Apr 06 2020