A302948 Number of nX3 0..1 arrays with every element equal to 1, 2, 3, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

1, 15, 86, 587, 3815, 25131, 164916, 1083375, 7114906, 46729709, 306907879, 2015697730, 13238601897, 86947883732, 571052268590, 3750530654213, 24632561409541, 161780595565168, 1062535099406293, 6978468794154813

Offset

1,2

Comments

Column 3 of A302953.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +15*a(n-2) +13*a(n-3) -2*a(n-4) -19*a(n-5) -3*a(n-6) +4*a(n-8)

Example

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

Crossrefs

Cf. A302953.

Sequence in context: A199897 A367228 A309922 * A230676 A232070 A219598

Adjacent sequences: A302945 A302946 A302947 * A302949 A302950 A302951

Keyword

nonn

Author

R. H. Hardin, Apr 16 2018

Status

approved