A203376 Number of (n+1)X7 0..1 arrays with every 2X2 subblock having equal diagonal elements or equal antidiagonal elements.

2916, 70996, 1764360, 44183028, 1109832180, 27913330472, 702420750924, 17679917387404, 445045123432096, 11203277447970636, 282028756620227124, 7099777698513424920, 178729975670304808348, 4499358353656818662428

Offset: 1

Author

R. H. Hardin Dec 31 2011

Keywords

• nonn

Comments

Column 6 of A203378

Examples

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

Links

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

Formula

Empirical: a(n) = 55*a(n-1) -1109*a(n-2) +11330*a(n-3) -67206*a(n-4) +247404*a(n-5) -582440*a(n-6) +881876*a(n-7) -846764*a(n-8) +499200*a(n-9) -172400*a(n-10) +33152*a(n-11) -3264*a(n-12) +128*a(n-13)