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

1,1

Links

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

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

Example

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

Crossrefs

Column 2 of A262274.

Sequence in context: A283692 A173712 A085697 * A231156 A271483 A223659

Adjacent sequences: A262265 A262266 A262267 * A262269 A262270 A262271

Keyword

nonn

Author

R. H. Hardin, Sep 17 2015

Status

approved