A252113 Number of (n+2) X (7+2) 0..3 arrays with every 3 X 3 subblock row and column sum equal to 0 2 3 6 or 7 and every 3 X 3 diagonal and antidiagonal sum not equal to 0 2 3 6 or 7.

2468, 1180, 2476, 4488, 11760, 17772, 33216, 84864, 142176, 265728, 678912, 1137408, 2125824, 5431296, 9099264, 17006592, 43450368, 72794112, 136052736, 347602944, 582352896, 1088421888, 2780823552, 4658823168, 8707375104

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 8*a(n-3) for n>8.

Empirical g.f.: 4*x*(617 + 295*x + 619*x^2 - 3814*x^3 + 580*x^4 - 509*x^5 - 672*x^6 - 2304*x^7) / ((1 - 2*x)*(1 + 2*x + 4*x^2)). - Colin Barker, Dec 01 2018

Example

Some solutions for n=4:
..0..1..1..0..1..1..0..1..1....3..0..3..0..0..2..0..0..2
..2..0..0..2..0..0..3..0..0....2..1..0..1..1..0..1..1..0
..0..1..1..0..1..1..0..1..1....1..1..0..1..1..0..1..1..0
..0..1..1..0..1..1..0..1..1....0..0..2..0..0..2..0..0..2
..3..0..0..2..0..0..2..0..0....1..1..0..1..1..0..1..1..0
..0..1..1..0..1..1..0..2..1....2..1..0..1..1..0..1..1..0

Crossrefs

Column 7 of A252114.

Sequence in context: A329240 A182381 A284089 * A102689 A082253 A253229

Adjacent sequences: A252110 A252111 A252112 * A252114 A252115 A252116

Keyword

nonn

Author

R. H. Hardin, Dec 14 2014

Status

approved