A258920 Number of (n+2) X (3+2) 0..1 arrays with no 3 x 3 subblock diagonal sum equal to the antidiagonal sum or central row sum equal to the central column sum.

1680, 1936, 1200, 1024, 1440, 1600, 1568, 1936, 2560, 2704, 2592, 3136, 4000, 4096, 3872, 4624, 5760, 5776, 5408, 6400, 7840, 7744, 7200, 8464, 10240, 10000, 9248, 10816, 12960, 12544, 11552, 13456, 16000, 15376, 14112, 16384, 19360, 18496, 16928

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) - 3*a(n-2) + 4*a(n-3) - 2*a(n-4) + 2*a(n-6) - 4*a(n-7) + 3*a(n-8) - 2*a(n-9) + a(n-10) for n>13.

Empirical g.f.: 16*x*(105 - 89*x + 148*x^2 - 143*x^3 - 87*x^4 + 54*x^5 - 148*x^6 + 171*x^7 + 11*x^8 + 39*x^9 + 4*x^10 - 22*x^11 - 25*x^12) / ((1 - x)^3*(1 + x)*(1 + x^2)^3). - Colin Barker, Dec 23 2018

Example

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

Crossrefs

Column 3 of A258921.

Sequence in context: A156425 A247853 A093787 * A268288 A175749 A231548

Adjacent sequences: A258917 A258918 A258919 * A258921 A258922 A258923

Keyword

nonn

Author

R. H. Hardin, Jun 14 2015

Status

approved