login
A302467
Number of nX3 0..1 arrays with every element equal to 1, 2, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
1, 14, 49, 250, 1147, 5486, 25599, 121626, 572657, 2702270, 12758927, 60200726, 284075917, 1340774674, 6327058239, 29858586774, 140911377557, 664983975698, 3138197357535, 14809850612998, 69890644606749, 329828551233330
OFFSET
1,2
COMMENTS
Column 3 of A302472.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) +9*a(n-2) +15*a(n-3) -68*a(n-4) -132*a(n-5) +96*a(n-6) +136*a(n-7) -34*a(n-8) -276*a(n-9) +188*a(n-10) -8*a(n-11) +32*a(n-12) -16*a(n-13) +64*a(n-14)
EXAMPLE
Some solutions for n=5
..0..0..0. .0..0..0. .0..1..1. .0..0..0. .0..1..1. .0..0..1. .0..0..1
..0..1..1. .1..0..1. .1..0..1. .1..1..0. .0..0..0. .1..1..0. .0..1..0
..0..0..1. .1..1..1. .1..1..1. .0..0..1. .1..1..1. .0..1..1. .1..1..1
..0..0..1. .1..1..0. .1..0..0. .0..0..1. .0..1..0. .1..0..0. .0..1..1
..0..1..1. .0..0..0. .0..0..0. .1..1..1. .0..0..1. .0..1..1. .0..0..0
CROSSREFS
Cf. A302472.
Sequence in context: A308834 A084049 A251221 * A303249 A215569 A246973
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 08 2018
STATUS
approved