A318541 Number of nX4 0..1 arrays with every element unequal to 0, 1, 4 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
5, 5, 13, 31, 78, 207, 516, 1288, 3270, 8271, 20866, 52679, 133064, 336062, 848616, 2143101, 5412264, 13667874, 34516655, 87168177, 220132818, 555919912, 1403912579, 3545419471, 8953548234, 22611157039, 57101877461, 144204222586
Offset: 1
Keywords
Examples
Some solutions for n=5 ..0..1..0..0. .0..0..0..0. .0..0..0..0. .0..0..0..0. .0..1..0..0 ..0..0..0..1. .1..0..0..1. .0..0..0..0. .0..0..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. .0..1..0..0. .1..0..0..0. .0..0..0..0 ..0..0..0..0. .0..0..1..0. .0..0..0..0. .0..0..0..0. .0..1..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A318545.
Formula
Empirical: a(n) = a(n-1) +7*a(n-3) +3*a(n-4) +10*a(n-5) -a(n-6) +4*a(n-7) -6*a(n-8) -a(n-9) -a(n-10) -a(n-12) +a(n-13) for n>14
Comments