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URL: https://oeis.org/A377003

⇱ A377003 - OEIS

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A377003
Number of inequivalent 2*n X 6 binary arrays with row sums 3 and column sums n up to row and column permutations.
2
1, 1, 3, 7, 19, 46, 132, 345, 951, 2457, 6198, 14816, 34126, 75057, 159176, 325021, 642473, 1230711, 2292826, 4160165, 7370620, 12768904, 21671722, 36080204, 59009291, 94910598, 150300578, 234560237, 361082376, 548722631, 823817750
OFFSET
0,3
EXAMPLE
The a(2) = 3 inequivalent matrices are:
[ 1 1 1 0 0 0 ] [ 1 1 1 0 0 0 ] [ 1 1 1 0 0 0 ]
[ 1 1 1 0 0 0 ] [ 1 1 0 1 0 0 ] [ 1 0 0 1 1 0 ]
[ 0 0 0 1 1 1 ] [ 0 0 1 0 1 1 ] [ 0 1 0 1 0 1 ]
[ 0 0 0 1 1 1 ] [ 0 0 0 1 1 1 ] [ 0 0 1 0 1 1 ]
CROSSREFS
Column k=3 of A377007.
Cf. A172556.
Sequence in context: A280756 A029855 A209397 * A110014 A026581 A151535
KEYWORD
nonn,more
AUTHOR
Andrew Howroyd, Oct 12 2024
STATUS
approved