A303681 Number of nX7 0..1 arrays with every element unequal to 0, 1 or 3 king-move adjacent elements, with upper left element zero.
21, 103, 57, 90, 150, 245, 367, 509, 697, 957, 1311, 1851, 2671, 3869, 5547, 7907, 11275, 16101, 22959, 32717, 46663, 66633, 95139, 135763, 193701, 276435, 394533, 563013, 803377, 1146445, 1636117, 2334893, 3331971, 4754851, 6785501, 9683407
Offset: 1
Keywords
Examples
Some solutions for n=5 ..0..0..0..0..0..1..1. .0..0..0..0..0..0..0. .0..0..0..0..0..0..0 ..0..0..0..0..0..0..1. .0..0..0..0..0..0..0. .0..0..0..0..0..0..0 ..0..0..0..0..0..0..0. .1..0..0..0..0..0..0. .0..0..0..0..0..0..1 ..1..0..0..0..0..0..0. .1..1..0..0..0..0..0. .0..0..0..0..0..1..1 ..1..1..0..0..0..0..0. .1..1..1..0..0..0..1. .1..0..0..0..1..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-8) for n>14
Comments