A268999 Number of 5Xn binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.
32, 379, 4083, 43512, 421450, 4097199, 38241770, 354861630, 3233293149, 29238488883, 261801167468, 2329097648405, 20588801089961, 181083224080162, 1585346158237184, 13824737077018333, 120130562347636272
Offset: 1
Keywords
Examples
Some solutions for n=4 ..0..0..0..0. .1..1..0..1. .1..0..0..1. .0..0..1..0. .0..1..0..0 ..1..1..0..1. .0..1..0..0. .0..1..0..0. .1..0..1..1. .0..0..0..0 ..0..1..0..0. .0..0..0..1. .1..0..0..1. .1..0..0..1. .0..0..0..1 ..0..0..1..0. .1..0..0..0. .1..0..0..1. .1..0..0..1. .1..0..0..1 ..0..0..0..1. .0..0..0..0. .0..0..0..1. .1..0..0..0. .0..0..0..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A268995.
Formula
Empirical: a(n) = 2*a(n-1) +97*a(n-2) +116*a(n-3) -2923*a(n-4) -10986*a(n-5) +4951*a(n-6) +72992*a(n-7) +36740*a(n-8) -223968*a(n-9) -159382*a(n-10) +423052*a(n-11) +256370*a(n-12) -539504*a(n-13) -176570*a(n-14) +450908*a(n-15) +6166*a(n-16) -217920*a(n-17) +57416*a(n-18) +45120*a(n-19) -25021*a(n-20) +562*a(n-21) +2089*a(n-22) -388*a(n-23) -31*a(n-24) +14*a(n-25) -a(n-26)
Comments