A301966 Number of 4Xn 0..1 arrays with every element equal to 0, 1 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.

8, 34, 40, 64, 111, 219, 443, 904, 1860, 3856, 8015, 16659, 34647, 72088, 150004, 312144, 649555, 1351723, 2812951, 5853784, 12181816, 25350576, 52755019, 109784179, 228462939, 475435704, 989390720, 2058940864, 4284695031

Offset

1,1

Comments

Row 4 of A301964.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +a(n-3) -a(n-4) -2*a(n-6) +a(n-7) for n>9

Example

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

Crossrefs

Cf. A301964.

Sequence in context: A299191 A300027 A301793 * A196143 A373356 A307091

Adjacent sequences: A301963 A301964 A301965 * A301967 A301968 A301969

Keyword

nonn

Author

R. H. Hardin, Mar 29 2018

Status

approved