A258961 Number of (n+2) X (3+2) 0..1 arrays with no 3 X 3 subblock diagonal sum 0 and no antidiagonal sum 3 and no row sum 0 or 3 and no column sum 0 or 3.

214, 274, 192, 286, 288, 412, 456, 670, 816, 1194, 1536, 2242, 2976, 4338, 5856, 8530, 11616, 16914, 23136, 33682, 46176, 67218, 92256, 134290, 184416, 268434, 368736, 536722, 737376, 1073298, 1474656, 2146450, 2949216, 4292754, 5898336, 8585362

Offset

1,1

Links

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

Formula

Empirical: a(n) = 3*a(n-2) - 2*a(n-4) for n>10.

Empirical g.f.: 2*x*(107 + 137*x - 225*x^2 - 268*x^3 + 70*x^4 + 51*x^5 - 12*x^6 + 3*x^7 + 12*x^8 + 4*x^9) / ((1 - x)*(1 + x)*(1 - 2*x^2)). - Colin Barker, Dec 24 2018

Example

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

Crossrefs

Column 3 of A258966.

Sequence in context: A335721 A242804 A076159 * A204486 A221807 A200043

Adjacent sequences: A258958 A258959 A258960 * A258962 A258963 A258964

Keyword

nonn

Author

R. H. Hardin, Jun 15 2015

Status

approved