A297539 Number of nX3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 or 3 neighboring 1s.
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
Keywords
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
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
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)
Comments