A250968 Number of (n+1)X(3+1) 0..1 arrays with no 2X2 subblock having the sum of its diagonal elements less than the absolute difference of its antidiagonal elements.

172, 1945, 22048, 249921, 2833397, 32124018, 364210219, 4129278507, 46816221866, 530784935436, 6017842440934, 68228062145830, 773544424316648, 8770159340495832, 99432808820402153, 1127332250873994176

Offset: 1

Author

R. H. Hardin, Nov 29 2014

Keywords

• nonn

Comments

Column 3 of A250973

Examples

			Some solutions for n=3
..0..1..0..1....0..1..0..1....1..1..1..0....1..0..0..1....1..0..0..0
..0..1..0..1....1..0..0..1....0..1..1..1....1..1..1..1....0..1..1..1
..1..0..0..1....1..1..1..1....1..1..1..0....1..0..1..0....0..1..1..0
..0..1..1..0....0..1..0..1....0..0..0..0....0..0..1..1....0..1..1..0
		

Links

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

Formula

Empirical: a(n) = 16*a(n-1) -68*a(n-2) +210*a(n-3) -492*a(n-4) +705*a(n-5) -675*a(n-6) +389*a(n-7) -120*a(n-8) +20*a(n-9)