A318542 Number of n X 5 0..1 arrays with every element unequal to 0, 1, 4 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
8, 8, 26, 78, 247, 784, 2349, 7191, 22268, 68384, 210050, 645832, 1985105, 6102355, 18758291, 57660242, 177244228, 544835790, 1674781291, 5148145759, 15824995614, 48644815851, 149530340549, 459644547764, 1412911535090, 4343179473160
Offset: 1
Keywords
Examples
Some solutions for n=5 ..0..0..0..0..0. .0..0..0..1..0. .0..0..1..0..0. .0..1..0..0..0 ..0..0..0..0..0. .1..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..0..0..1..0 ..1..0..0..0..0. .0..1..0..0..0. .1..0..0..0..0. .0..0..0..0..0 ..0..0..0..1..0. .0..0..0..0..0. .0..0..1..0..0. .0..0..0..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) +14*a(n-3) +7*a(n-4) +33*a(n-5) -6*a(n-6) +20*a(n-7) -48*a(n-8) -4*a(n-9) -32*a(n-10) +30*a(n-12) +14*a(n-13) -8*a(n-14) -10*a(n-15) +9*a(n-16) -3*a(n-17) -13*a(n-18) +9*a(n-19) +7*a(n-20) -5*a(n-21) -a(n-22) +a(n-23) for n>24.
Comments