A302803 Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
4, 29, 169, 1010, 6084, 36456, 218640, 1312416, 7873344, 47237760, 283440384, 1700614656, 10203632640, 61222127616, 367332102144, 2203991285760, 13223955677184, 79343718137856, 476062276976640, 2856373852962816
Offset: 1
Keywords
Examples
Some solutions for n=5 ..0..0..0. .0..0..0. .0..0..0. .0..1..0. .0..0..0. .0..0..1. .0..1..1 ..1..1..0. .1..1..0. .1..0..0. .0..0..1. .1..1..0. .1..1..1. .1..0..1 ..1..0..1. .0..0..0. .1..1..1. .1..0..1. .0..0..0. .1..0..1. .0..1..1 ..0..0..1. .0..0..0. .1..1..1. .1..0..1. .1..0..1. .0..0..1. .0..1..0 ..0..1..1. .0..0..1. .0..0..1. .1..0..0. .0..1..1. .1..1..1. .0..0..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A302808.
Formula
Empirical: a(n) = 6*a(n-1) +24*a(n-3) -144*a(n-4) for n>6
Comments