A057149 Triangle T(n,k) of n X n binary matrices with k ones, with no zero rows or columns, up to row and column permutation.
0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 2, 5, 4, 3, 1, 1, 0, 0, 0, 0, 1, 2, 11, 21, 34, 33, 33, 19, 14, 6, 3, 1, 1, 0, 0, 0, 0, 0, 1, 2, 14, 49, 131, 248, 410, 531, 601, 566, 474, 336, 222, 124, 67, 32, 16, 6, 3, 1, 1, 0, 0, 0, 0, 0, 0, 1, 2, 15, 69, 288, 840, 2144, 4488, 8317, 13160
Offset: 1
Examples
[0,1], [0,0,1,1,1], [0,0,0,1,2,5,4,3,1,1],...; T(4,6)=11, i.e. there are 11 4 X 4 binary matrices with 6 ones, with no zero rows or columns, up to row and column permutation: [0 0 0 1] [0 0 0 1] [0 0 0 1] [0 0 0 1] [0 0 0 1] [0 0 0 1] [0 0 0 1] [0 0 0 1] [0 0 0 1] [0 0 0 1] [0 0 0 1] [0 0 1 0] [0 0 0 1] [0 0 1 0] [0 0 1 0] [0 0 1 1] [0 1 1 0] [0 0 1 1] [1 1 1 0] [1 1 0 1] [1 1 1 0] [1 1 0 0] [1 0 1 0] [1 1 0 0] and [0 0 0 1] [0 0 0 1] [0 0 0 1] [0 0 0 1] [0 0 0 1] [0 0 1 0] [0 0 1 0] [0 0 1 0] [0 0 1 0] [0 0 1 0] [0 1 0 0] [0 1 0 1] [0 1 0 1] [0 1 0 1] [1 1 0 0] [1 0 1 1] [1 0 0 1] [1 0 1 0] [1 1 0 0] [1 1 0 0].
Links
- Sean A. Irvine, Table of n, a(n) for n = 1..1029
- Sean A. Irvine, Java program (github)
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