A302511 Number of nX4 0..1 arrays with every element equal to 0, 1, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

5, 5, 15, 28, 48, 89, 163, 297, 544, 1004, 1848, 3393, 6237, 11481, 21122, 38834, 71418, 131383, 241665, 444451, 817450, 1503590, 2765570, 5086571, 9355603, 17207807, 31650188, 58213496, 107071156, 196935005, 362220199, 666226093, 1225380420

Offset

1,1

Comments

Column 4 of A302515.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = a(n-1) +2*a(n-3) +2*a(n-4) -a(n-6) -a(n-7) for n>10

Example

Some solutions for n=5
..0..1..0..1. .0..1..0..1. .0..0..1..0. .0..1..1..1. .0..0..0..1
..0..1..0..1. .0..1..0..1. .1..1..1..0. .0..1..0..1. .0..1..0..1
..0..0..1..1. .0..1..0..1. .1..0..0..0. .0..0..0..1. .0..1..1..1
..0..1..0..1. .0..1..1..1. .1..0..1..0. .0..1..1..1. .0..0..0..1
..0..1..0..1. .0..1..0..0. .1..1..1..0. .0..1..0..0. .0..1..0..1

Crossrefs

Cf. A302515.

Sequence in context: A341244 A050341 A140360 * A178821 A145599 A275016

Adjacent sequences: A302508 A302509 A302510 * A302512 A302513 A302514

Keyword

nonn

Author

R. H. Hardin, Apr 09 2018

Status

approved