A297502 Number of nX4 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 2 neighboring 1s.

7, 68, 314, 2281, 14201, 88808, 573119, 3613793, 22999331, 146183595, 928047561, 5898371728, 37468267405, 238038322708, 1512327060362, 9607753234896, 61039432234655, 387788945511548, 2463656446529920, 15651856594703719

Offset

1,1

Comments

Column 4 of A297506.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +19*a(n-2) +58*a(n-3) -7*a(n-4) -41*a(n-5) -196*a(n-6) -202*a(n-7) -78*a(n-8) +196*a(n-9) +176*a(n-10) +122*a(n-11) +19*a(n-12) +37*a(n-13) +22*a(n-14) +21*a(n-15) +10*a(n-16) -a(n-17) -a(n-18)

Example

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

Crossrefs

Cf. A297506.

Sequence in context: A093170 A294664 A120079 * A087567 A328046 A371392

Adjacent sequences: A297499 A297500 A297501 * A297503 A297504 A297505

Keyword

nonn

Author

R. H. Hardin, Dec 31 2017

Status

approved