A256803 Number of (n+2) X (1+2) 0..1 arrays with no 3 x 3 subblock diagonal sum 0 and no antidiagonal sum 0 and no row sum 0 or 1 and no column sum 0 or 1.

32, 86, 237, 641, 1731, 4690, 12707, 34408, 93168, 252313, 683305, 1850413, 5011000, 13570213, 36749148, 99519030, 269504389, 729837077, 1976449263, 5352360678, 14494564867, 39252288748, 106297917568, 287862131449, 779550625853

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-1) + a(n-2) + 7*a(n-3) + 7*a(n-4) + 3*a(n-5) - a(n-6) - 6*a(n-7) - 2*a(n-8).

Empirical g.f.: x*(32 + 54*x + 119*x^2 + 94*x^3 + 27*x^4 - 39*x^5 - 86*x^6 - 26*x^7) / (1 - x - x^2 - 7*x^3 - 7*x^4 - 3*x^5 + x^6 + 6*x^7 + 2*x^8). - Colin Barker, Dec 20 2018

Example

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

Crossrefs

Column 1 of A256810.

Sequence in context: A044170 A044551 A256810 * A229721 A184029 A184021

Adjacent sequences: A256800 A256801 A256802 * A256804 A256805 A256806

Keyword

nonn

Author

R. H. Hardin, Apr 10 2015

Status

approved