A302954 Number of 3Xn 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.

0, 11, 86, 519, 3626, 26167, 185810, 1317541, 9353154, 66404553, 471405566, 3346494089, 23756835310, 168650322345, 1197251824916, 8499313431065, 60336790015098, 428332035511083, 3040737367321452, 21586253123647687

Offset

1,2

Comments

Row 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) +37*a(n-3) +80*a(n-4) +68*a(n-5) +26*a(n-6) +5*a(n-7) for n>9

Example

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

Crossrefs

Cf. A302953.

Sequence in context: A344480 A320940 A012794 * A014917 A080962 A243879

Adjacent sequences: A302951 A302952 A302953 * A302955 A302956 A302957

Keyword

nonn

Author

R. H. Hardin, Apr 16 2018

Status

approved