A268786 Number of nX5 binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.
10, 131, 1144, 9085, 67100, 477128, 3295246, 22302699, 148575958, 977609634, 6368239274, 41140907455, 263939673228, 1683296018391, 10680625988516, 67468330344536, 424526386272378, 2661981983940811, 16640406499054332
Offset: 1
Keywords
Examples
Some solutions for n=4 ..0..0..0..0..0. .0..1..1..0..0. .0..0..0..0..0. .0..1..0..0..1 ..0..1..0..0..1. .0..0..0..0..1. .0..0..1..0..1. .0..0..0..1..0 ..0..0..1..0..0. .0..1..0..0..0. .1..0..0..0..0. .0..0..0..0..1 ..0..0..1..0..0. .0..0..1..0..1. .1..0..0..0..1. .1..0..1..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A268789.
Formula
Empirical: a(n) = 2*a(n-1) +41*a(n-2) +54*a(n-3) -509*a(n-4) -2182*a(n-5) -2830*a(n-6) +1766*a(n-7) +7914*a(n-8) +2584*a(n-9) -10583*a(n-10) -6092*a(n-11) +11506*a(n-12) +5348*a(n-13) -11688*a(n-14) -620*a(n-15) +9251*a(n-16) -4462*a(n-17) -3137*a(n-18) +4774*a(n-19) -2365*a(n-20) +338*a(n-21) +198*a(n-22) -106*a(n-23) +12*a(n-24) +4*a(n-25) -a(n-26)
Comments