A203563 Number of nX7 0..2 arrays with row sums equal and column sums equal.
3, 395, 35619, 7343451, 1509893003, 360255871643
Offset: 1
Keywords
Examples
Some solutions for n=4 ..0..1..2..0..1..1..2....0..2..1..1..1..0..2....0..2..0..1..2..0..2 ..2..1..0..1..1..2..0....0..0..0..1..2..2..2....1..0..0..2..2..1..1 ..0..1..2..2..1..0..1....2..1..2..1..0..1..0....1..2..2..1..0..1..0 ..2..1..0..1..1..1..1....2..1..1..1..1..1..0....2..0..2..0..0..2..1
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