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.

A297539 Number of nX3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 or 3 neighboring 1s.

Original entry on oeis.org

1, 11, 35, 88, 461, 2050, 8057, 35640, 158090, 679629, 2963173, 12981912, 56560118, 246687460, 1077347659, 4701310128, 20514731834, 89541862920, 390793087220, 1705499848917, 7443466123759, 32485974265409, 141779148752373
Offset: 1

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Author

R. H. Hardin, Dec 31 2017

Keywords

Comments

Column 3 of A297544.

Examples

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

Crossrefs

Cf. A297544.

Formula

Empirical: a(n) = 3*a(n-1) +38*a(n-3) -40*a(n-4) +7*a(n-5) -296*a(n-6) +98*a(n-7) +36*a(n-8) +388*a(n-9) -96*a(n-10) -104*a(n-11) +400*a(n-12) -192*a(n-13) +128*a(n-14)