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.

A297678 Number of nX4 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0, 1 or 4 neighboring 1s.

Original entry on oeis.org

13, 80, 629, 4633, 34872, 260924, 1955750, 14651847, 109783269, 822547725, 6162992737, 46176452589, 345979170190, 2592263829464, 19422650189445, 145525052534819, 1090352803546358, 8169515919608631, 61210454258421286
Offset: 1

Views

Author

R. H. Hardin, Jan 03 2018

Keywords

Comments

Column 4 of A297682.

Examples

			Some solutions for n=5
..1..0..0..0. .1..0..1..0. .0..0..0..1. .1..1..0..0. .0..0..0..0
..0..1..0..0. .1..0..1..0. .1..1..0..0. .0..0..0..1. .0..0..0..1
..0..1..0..1. .1..1..1..0. .0..0..0..0. .0..0..0..0. .1..0..0..1
..0..0..0..0. .0..0..0..0. .1..0..0..1. .0..0..0..0. .0..0..0..1
..0..1..0..1. .0..0..0..0. .1..0..1..0. .0..0..0..0. .1..0..1..0
		

Crossrefs

Cf. A297682.

Formula

Empirical: a(n) = 6*a(n-1) +10*a(n-2) +6*a(n-3) +26*a(n-4) -31*a(n-5) -a(n-6) -165*a(n-7) -22*a(n-8) +181*a(n-9) +39*a(n-10) -54*a(n-11) -15*a(n-12) +6*a(n-13) -4*a(n-14) -a(n-15) +2*a(n-16)