A262753 Number of (n+2) X (2+2) 0..1 arrays with each row divisible by 5 and each column divisible by 7, read as a binary number with top and left being the most significant bits.

4, 9, 25, 100, 361, 1369, 5476, 21609, 85849, 343396, 1371241, 5480281, 21921124, 87665769, 350625625, 1402502500, 5609860201, 22439141209, 89756564836, 359025060969, 1436097847129, 5744391388516, 22977555967081, 91910204694361

Offset: 1

Author

R. H. Hardin, Sep 30 2015

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 2 of A262759.

Formula

Empirical: a(n) = 4*a(n-1) + 9*a(n-3) - 36*a(n-4) - 8*a(n-6) + 32*a(n-7).

Empirical g.f.: x*(4 - 7*x - 11*x^2 - 36*x^3 + 24*x^4 + 24*x^5 + 32*x^6) / ((1 - x)*(1 - 2*x)*(1 - 4*x)*(1 + x + x^2)*(1 + 2*x + 4*x^2)). - Colin Barker, Dec 31 2018