A301820 Number of nX5 0..1 arrays with every element equal to 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero.

3, 18, 74, 299, 1197, 4785, 19130, 76499, 305959, 1223777, 4895020, 19579955, 78319649, 313278369, 1253113182, 5012452355, 20049808955, 80199235249, 320796940304, 1283187760387, 5132751040565, 20531004161105, 82124016643074

Offset

1,1

Comments

Column 5 of A301823.

Links

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

Formula

Empirical: a(n) = 8*a(n-1) -22*a(n-2) +28*a(n-3) -17*a(n-4) +4*a(n-5) for n>7

Example

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

Crossrefs

Cf. A301823.

Sequence in context: A280804 A152897 A059393 * A094033 A245580 A043008

Adjacent sequences: A301817 A301818 A301819 * A301821 A301822 A301823

Keyword

nonn

Author

R. H. Hardin, Mar 27 2018

Status

approved