cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A208115 Number of n X 5 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 0 1 1 vertically.

Original entry on oeis.org

15, 225, 825, 3025, 7315, 17689, 34713, 68121, 117711, 203401, 322465, 511225, 761475, 1134225, 1611345, 2289169, 3133423, 4289041, 5697321, 7568001, 9807315, 12709225, 16131625, 20475625, 25534575, 31843449, 39111633, 48038761, 58227331
Offset: 1

Views

Author

R. H. Hardin, Feb 23 2012

Keywords

Comments

Column 5 of A208118.

Examples

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

Crossrefs

Cf. A208118.

Formula

Empirical: a(n) = 2*a(n-1) + 4*a(n-2) - 10*a(n-3) - 5*a(n-4) + 20*a(n-5) - 20*a(n-7) + 5*a(n-8) + 10*a(n-9) - 4*a(n-10) - 2*a(n-11) + a(n-12).
Empirical g.f.: x*(15 + 195*x + 315*x^2 + 625*x^3 + 290*x^4 + 34*x^5 - 50*x^6 + 14*x^7 + 7*x^8 - 5*x^9 - x^10 + x^11) / ((1 - x)^7*(1 + x)^5). - Colin Barker, Jun 28 2018