A258891 Number of (n+2) X (5+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.

30870, 23409, 12804, 9604, 12544, 16384, 21320, 27556, 35360, 44944, 56680, 70756, 87680, 107584, 131144, 158404, 190240, 226576, 268520, 315844, 369920, 430336, 498760, 574564, 659744, 753424, 857960, 972196, 1098880, 1236544, 1388360

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 + 149*n^2 + 620*n + 3844 for n>3.

Empirical for n mod 2 = 1: a(n) = n^4 + 10*n^3 + 150*n^2 + 610*n + 3869 for n>3.

Empirical g.f.: x*(30870 - 38331*x - 95754*x^2 + 122398*x^3 + 108182*x^4 - 136308*x^5 - 57626*x^6 + 59146*x^7 + 19844*x^8 - 6825*x^9 - 5404*x^10) / ((1 - x)^5*(1 + x)^3). - Colin Barker, Dec 23 2018

Example

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

Crossrefs

Column 5 of A258894.

Sequence in context: A269828 A270057 A236899 * A237469 A071124 A250590

Adjacent sequences: A258888 A258889 A258890 * A258892 A258893 A258894

Keyword

nonn

Author

R. H. Hardin, Jun 14 2015

Status

approved