A253396 Number of (n+1)X(7+1) 0..1 arrays with every 2X2 subblock antidiagonal maximum minus diagonal minimum nondecreasing horizontally and diagonal maximum minus antidiagonal minimum nondecreasing vertically.

704, 391, 520, 823, 1269, 1855, 2726, 3810, 5311, 7163, 9569, 12493, 16140, 20493, 25773, 31978, 39346, 47891, 57867, 69304, 82472, 97417, 114425, 133558, 155118, 179183, 206071, 235876, 268932, 305349, 345477, 389442, 437610, 490123, 547363

Offset: 1

Author

R. H. Hardin, Dec 31 2014

Keywords

• nonn

Comments

Column 7 of A253397

Examples

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

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -5*a(n-2) +5*a(n-4) -4*a(n-5) +a(n-6) for n>18

Empirical for n mod 2 = 0: a(n) = (1/3)*n^4 - (1/3)*n^3 + (337/6)*n^2 - (1423/6)*n + 914 for n>12

Empirical for n mod 2 = 1: a(n) = (1/3)*n^4 - (1/3)*n^3 + (337/6)*n^2 - (1423/6)*n + 943 for n>12