A268889 Number of 4Xn binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.
0, 71, 462, 4133, 27130, 186732, 1187838, 7529253, 46440962, 283673207, 1710265892, 10226321520, 60660804228, 357586190291, 2096177689750, 12229766790505, 71054027831574, 411303965509420, 2373090804832634
Offset: 1
Keywords
Examples
Some solutions for n=4 ..0..0..0..0. .1..0..1..0. .1..0..0..1. .1..0..0..0. .0..1..0..1 ..0..0..1..0. .0..0..0..0. .1..0..1..0. .1..0..1..0. .1..0..0..1 ..0..0..1..0. .1..0..1..0. .1..0..0..1. .0..1..0..0. .0..1..0..0 ..0..1..0..1. .0..1..0..1. .0..1..0..0. .0..0..0..0. .0..0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A268886.
Formula
Empirical: a(n) = 2*a(n-1) +39*a(n-2) +14*a(n-3) -482*a(n-4) -1102*a(n-5) -111*a(n-6) +1758*a(n-7) +982*a(n-8) -1114*a(n-9) -743*a(n-10) +394*a(n-11) +206*a(n-12) -90*a(n-13) -17*a(n-14) +10*a(n-15) -a(n-16)
Comments