A297937 Number of nX2 0..1 arrays with every element equal to 0, 2, 3 or 5 king-move adjacent elements, with upper left element zero.

1, 5, 7, 18, 31, 65, 130, 253, 519, 1018, 2055, 4097, 8186, 16405, 32743, 65570, 131055, 262145, 524338, 1048493, 2097287, 4194186, 8388695, 16777281, 33554218, 67109317, 134217191, 268436018, 536870719, 1073741505, 2147484898, 4294965341

Offset

1,2

Comments

Column 2 of A297943.

Links

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

Formula

Empirical: a(n) = a(n-1) +3*a(n-2) -4*a(n-4) for n>5

Example

Some solutions for n=7
..0..1. .0..0. .0..0. .0..1. .0..1. .0..0. .0..0. .0..0. .0..0. .0..0
..0..0. .1..0. .0..0. .0..0. .1..1. .0..1. .0..0. .0..0. .0..0. .1..0
..1..0. .1..1. .0..0. .1..1. .1..0. .1..1. .0..0. .0..0. .0..0. .1..1
..1..1. .0..0. .0..0. .1..0. .0..0. .0..1. .1..1. .1..1. .0..0. .1..0
..1..0. .0..0. .0..0. .0..0. .1..0. .0..0. .1..1. .1..0. .0..0. .0..0
..0..0. .1..1. .1..1. .1..1. .1..1. .1..1. .0..0. .0..0. .1..1. .1..0
..1..0. .1..0. .1..1. .1..1. .0..1. .1..0. .0..1. .1..0. .0..1. .1..1

Crossrefs

Cf. A297943.

Sequence in context: A214414 A153192 A263878 * A337349 A028319 A116640

Adjacent sequences: A297934 A297935 A297936 * A297938 A297939 A297940

Keyword

nonn

Author

R. H. Hardin, Jan 09 2018

Status

approved