A303678 Number of nX4 0..1 arrays with every element unequal to 0, 1 or 3 king-move adjacent elements, with upper left element zero.
5, 17, 15, 28, 44, 64, 90, 132, 204, 312, 466, 688, 1024, 1540, 2318, 3472, 5184, 7748, 11606, 17396, 26052, 38984, 58338, 87340, 130788, 195824, 293146, 438824, 656952, 983564, 1472534, 2204504, 3300280, 4940796, 7396894, 11073932, 16578716
Offset: 1
Keywords
Examples
Some solutions for n=5 ..0..0..0..1. .0..0..0..0. .0..1..1..1. .0..1..1..1. .0..1..1..1 ..0..0..0..0. .0..0..0..0. .0..0..1..1. .1..1..1..1. .1..1..1..1 ..1..0..0..0. .0..0..0..1. .0..0..0..1. .1..1..1..1. .1..1..1..1 ..1..1..0..0. .0..0..1..1. .0..0..0..0. .1..1..1..1. .0..1..1..1 ..1..1..1..0. .0..1..1..1. .1..0..0..0. .0..1..1..0. .0..0..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A303682.
Formula
Empirical: a(n) = a(n-1) +a(n-4) +a(n-5) for n>8
Comments