A268764 Number of nX6 binary arrays with some element plus some horizontally, vertically, diagonally or antidiagonally adjacent neighbor totalling two exactly once.
20, 258, 2607, 23156, 193573, 1552272, 12111209, 92571436, 696659613, 5178525870, 38112289517, 278191828634, 2016589831189, 14532118028260, 104191269908219, 743719988895596, 5288057396240333, 37470071363668612, 264689231027772351
Offset: 1
Keywords
Examples
Some solutions for n=4 ..0..0..0..0..0..1. .0..1..1..0..0..1. .0..0..0..0..0..0. .0..1..0..0..0..1 ..0..0..1..1..0..0. .0..0..0..0..0..0. .0..0..0..0..1..1. .0..0..0..0..0..1 ..0..0..0..0..0..0. .0..1..0..0..1..0. .1..0..0..0..0..0. .0..0..1..0..0..0 ..0..1..0..0..0..1. .0..0..0..0..0..0. .0..0..1..0..0..0. .1..0..0..0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A268766.
Formula
Empirical: a(n) = 6*a(n-1) +51*a(n-2) -214*a(n-3) -1074*a(n-4) +2018*a(n-5) +7713*a(n-6) -10572*a(n-7) -22926*a(n-8) +30116*a(n-9) +25283*a(n-10) -32400*a(n-11) -15148*a(n-12) +15184*a(n-13) +5660*a(n-14) -2688*a(n-15) -1024*a(n-16)
Comments