A255785 Number of (n+2) X (1+2) 0..1 arrays with no 3 x 3 subblock diagonal sum 2 and no antidiagonal sum 2 and no row sum 0 and no column sum 0.

90, 177, 361, 715, 1478, 2969, 6186, 12534, 26219, 53487, 112079, 229756, 481725, 990964, 2077526, 4284777, 8978859, 18554317, 38857870, 80416809, 168307678, 348718298, 729394343, 1512628937, 3162067127, 6562395892, 13711273601

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-1) + 5*a(n-2) - 2*a(n-3) - 6*a(n-4) - 7*a(n-5) + 6*a(n-6) + 3*a(n-7) - 6*a(n-8) + 5*a(n-9) + 5*a(n-10) + 5*a(n-11) + 2*a(n-12).

Empirical g.f.: x*(90 + 87*x - 266*x^2 - 351*x^3 - 148*x^4 + 330*x^5 + 122*x^6 - 56*x^7 + 409*x^8 + 369*x^9 + 282*x^10 + 88*x^11) / ((1 + x)*(1 - 2*x - 3*x^2 + 5*x^3 + x^4 + 6*x^5 - 12*x^6 + 9*x^7 - 3*x^8 - 2*x^9 - 3*x^10 - 2*x^11)). - Colin Barker, Dec 19 2018

Example

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

Crossrefs

Column 1 of A255792.

Sequence in context: A119895 A270266 A255792 * A366740 A119896 A179697

Adjacent sequences: A255782 A255783 A255784 * A255786 A255787 A255788

Keyword

nonn

Author

R. H. Hardin, Mar 06 2015

Status

approved