A262268 Number of (n+2) X (2+2) 0..1 arrays with each row and column divisible by 5, read as a binary number with top and left being the most significant bits.

4, 16, 49, 169, 676, 2704, 10609, 42025, 168100, 672400, 2686321, 10738729, 42954916, 171819664, 687226225, 2748800041, 10995200164, 43980800656, 175922363761, 703687777321, 2814751109284, 11259004437136, 45036004326769

Offset: 1

Author

R. H. Hardin, Sep 17 2015

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 2 of A262274.

Formula

Empirical: a(n) = 6*a(n-1) - 12*a(n-2) + 24*a(n-3) - 31*a(n-4) - 6*a(n-5) + 12*a(n-6) - 24*a(n-7) + 32*a(n-8).

Empirical g.f.: x*(4 - 8*x + x^2 - 29*x^3 - 10*x^4 + 20*x^5 + 8*x^6 + 32*x^7) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 - 4*x)*(1 + x^2)*(1 + 4*x^2)). - Colin Barker, Dec 31 2018