A258892 Number of (n+2) X (6+2) 0..1 arrays with no 3 x 3 subblock diagonal sum less than the antidiagonal sum or central row sum less than the central column sum.

94249, 51188, 20164, 13221, 16384, 21025, 26244, 33485, 41616, 52425, 64516, 80053, 97344, 118961, 142884, 172125, 204304, 242905, 285156, 335045, 389376, 452673, 521284, 600301, 685584, 782825, 887364, 1005525, 1132096, 1274065, 1425636

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + 2*a(n-2) - 6*a(n-3) + 6*a(n-5) - 2*a(n-6) - 2*a(n-7) + a(n-8) for n>11.

Empirical for n mod 2 = 0: a(n) = n^4 + 10*n^3 + 182*n^2 + 802*n + 6205 for n>3.

Empirical for n mod 2 = 1: a(n) = n^4 + 10*n^3 + 181*n^2 + 780*n + 6084 for n>3.

Empirical g.f.: x*(94249 - 137310*x - 270710*x^2 + 436011*x^3 + 256742*x^4 - 482695*x^5 - 87878*x^6 + 207141*x^7 + 17437*x^8 - 23035*x^9 - 9760*x^10) / ((1 - x)^5*(1 + x)^3). - Colin Barker, Dec 23 2018

Example

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

Crossrefs

Column 6 of A258894.

Sequence in context: A126708 A209514 A029754 * A204473 A031675 A254977

Adjacent sequences: A258889 A258890 A258891 * A258893 A258894 A258895

Keyword

nonn

Author

R. H. Hardin, Jun 14 2015

Status

approved