A269279 Number of 4Xn 0..3 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling three exactly once.
0, 20412, 1365336, 74853576, 3719884392, 174924572760, 7934992835112, 350946381867480, 15232155757251048, 651580499598523992, 27551808205246504872, 1154085846201751972824, 47965168186749101620584
Offset: 1
Keywords
Examples
Some solutions for n=2 ..0..3. .2..0. .1..3. .1..3. .0..2. .0..2. .0..1. .0..2. .0..1. .1..3 ..3..3. .0..0. .0..0. .3..1. .3..3. .3..2. .3..2. .2..3. .3..1. .2..2 ..2..2. .1..3. .2..2. .2..2. .0..2. .1..0. .0..1. .3..2. .3..0. .1..3 ..0..2. .1..2. .0..1. .3..2. .2..3. .0..2. .1..2. .1..3. .0..0. .1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A269276.
Formula
Empirical: a(n) = 96*a(n-1) -3108*a(n-2) +40720*a(n-3) -265326*a(n-4) +931200*a(n-5) -1766452*a(n-6) +1678992*a(n-7) -622521*a(n-8) for n>12
Comments