A297649 Number of nX3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1, 2 or 3 neighboring 1s.

4, 43, 231, 1421, 9033, 55706, 346032, 2151932, 13364992, 83036263, 515911384, 3205231551, 19913717003, 123721335945, 768662962676, 4775598530205, 29670139081754, 184336490377417, 1145257318539730, 7115326466070793

Offset

1,1

Comments

Column 3 of A297654.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +9*a(n-2) +60*a(n-3) +51*a(n-4) +54*a(n-5) -303*a(n-6) -336*a(n-7) -234*a(n-8) +316*a(n-9) +264*a(n-10) -144*a(n-11)

Example

Some solutions for n=6
..1..1..1. .0..0..0. .0..1..1. .0..0..1. .1..1..0. .0..0..0. .0..1..0
..1..1..0. .0..1..1. .1..0..1. .1..1..0. .0..0..1. .0..1..0. .0..0..1
..0..0..0. .0..0..0. .1..1..0. .0..0..0. .1..1..1. .0..1..1. .1..0..1
..0..0..0. .0..0..0. .0..1..0. .1..1..1. .0..0..0. .0..1..1. .0..1..0
..1..1..1. .1..1..0. .0..0..1. .0..1..1. .1..1..0. .0..1..0. .0..1..1
..0..1..0. .1..0..1. .0..1..1. .0..1..0. .1..0..0. .1..0..1. .0..0..0

Crossrefs

Cf. A297654.

Sequence in context: A198209 A220774 A296683 * A186678 A186768 A130545

Adjacent sequences: A297646 A297647 A297648 * A297650 A297651 A297652

Keyword

nonn

Author

R. H. Hardin, Jan 02 2018

Status

approved