VOOZH about

URL: https://oeis.org/A258890

⇱ A258890 - OEIS

login
A258890
Number of (n+2) X (4+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.
1
10201, 10680, 8100, 7225, 9604, 13221, 17424, 23393, 30276, 39565, 50176, 63945, 79524, 99125, 121104, 148081, 178084, 214173, 254016, 301145, 352836, 413125, 478864, 554625, 636804, 730541, 831744, 946153, 1069156, 1207125, 1354896
OFFSET
1,1
LINKS
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 + 122*n^2 + 498*n + 2385 for n>3.
Empirical for n mod 2 = 1: a(n) = n^4 + 10*n^3 + 121*n^2 + 480*n + 2304 for n>3.
Empirical g.f.: x*(10201 - 9722*x - 33662*x^2 + 30871*x^3 + 43034*x^4 - 33043*x^5 - 28554*x^6 + 12889*x^7 + 11977*x^8 - 883*x^9 - 2916*x^10) / ((1 - x)^5*(1 + x)^3). - Colin Barker, Dec 22 2018
EXAMPLE
Some solutions for n=4:
..0..1..0..0..0..1....0..1..0..1..0..1....1..0..0..0..0..0....1..0..1..0..0..1
..1..1..0..1..0..0....1..1..1..1..1..0....1..0..0..0..0..0....1..1..0..1..0..1
..1..0..1..0..1..1....1..1..1..1..1..1....0..0..0..0..0..1....1..0..1..0..1..1
..1..1..0..1..0..1....1..1..1..1..1..1....0..0..0..0..0..0....0..1..0..1..0..1
..1..0..1..0..1..1....0..1..1..1..1..1....0..0..0..0..0..1....0..0..1..0..1..1
..0..1..0..1..0..1....1..0..1..1..1..1....0..0..0..0..0..1....0..0..0..0..1..1
CROSSREFS
Column 4 of A258894.
Sequence in context: A221119 A105582 A243819 * A255872 A291925 A255880
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 14 2015
STATUS
approved