A302510 Number of n X 3 0..1 arrays with every element equal to 0, 1, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

3, 3, 11, 9, 14, 21, 28, 37, 51, 72, 100, 137, 188, 260, 360, 497, 685, 945, 1305, 1802, 2487, 3432, 4737, 6539, 9026, 12458, 17195, 23734, 32760, 45218, 62413, 86147, 118907, 164125, 226538, 312685, 431592, 595717, 822255, 1134940, 1566532

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-1) +a(n-4) for n>7.

Example

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

Crossrefs

Column 3 of A302515.

Sequence in context: A073106 A309692 A107229 * A164900 A304082 A122167

Adjacent sequences: A302507 A302508 A302509 * A302511 A302512 A302513

Keyword

nonn

Author

R. H. Hardin, Apr 09 2018

Status

approved