A269190 Number of nX4 0..3 arrays with some element plus some horizontally, diagonally, antidiagonally or vertically adjacent neighbor totalling three no more than once.
216, 4476, 115452, 2817548, 67134380, 1567933676, 36068275268, 819789099172, 18452018423420, 411983259384452, 9136178140885388, 201433537180523700, 4419013543755451812, 96521322466937887324, 2100165198065619059932
Offset: 1
Keywords
Examples
Some solutions for n=3 ..0..0..3..1. .3..3..3..3. .3..3..1..3. .0..0..0..0. .0..1..0..2 ..1..1..1..1. .3..1..3..1. .1..3..1..0. .1..0..0..0. .2..0..0..2 ..1..0..1..0. .1..3..1..3. .1..3..1..1. .2..0..1..1. .2..2..2..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A269194.
Formula
Empirical: a(n) = 46*a(n-1) -607*a(n-2) +1264*a(n-3) +11029*a(n-4) -27640*a(n-5) -86627*a(n-6) +153412*a(n-7) +308464*a(n-8) -329306*a(n-9) -438615*a(n-10) +260680*a(n-11) +134834*a(n-12) -65824*a(n-13) -9889*a(n-14) +5080*a(n-15) -400*a(n-16) for n>17
Comments