A298569 Number of nX2 0..1 arrays with every element equal to 0, 2, 4, 5 or 7 king-move adjacent elements, with upper left element zero.

1, 4, 4, 8, 36, 52, 100, 356, 628, 1220, 3668, 7268, 14516, 38980, 82452, 169508, 423284, 926980, 1953236, 4661476, 10384180, 22302148, 51781012, 116208548, 253089012, 578128516, 1300672852, 2860550756, 6473222836, 14566091588

Offset

1,2

Comments

Column 2 of A298575.

Links

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

Formula

Empirical: a(n) = a(n-1) +8*a(n-3) -4*a(n-4)

Example

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

Crossrefs

Cf. A298575.

Sequence in context: A137717 A096252 A102369 * A281717 A205971 A118016

Adjacent sequences: A298566 A298567 A298568 * A298570 A298571 A298572

Keyword

nonn

Author

R. H. Hardin, Jan 22 2018

Status

approved