A302966 Number of 3Xn 0..1 arrays with every element equal to 0, 1, 2, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

4, 32, 154, 786, 3924, 19868, 100161, 505908, 2554201, 12898093, 65130456, 328890172, 1660800969, 8386586118, 42349950959, 213855666444, 1079912639341, 5453263882696, 27537493309346, 139056822182155, 702198983497508

Offset

1,1

Comments

Row 3 of A302965.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +15*a(n-2) -11*a(n-3) -64*a(n-4) -10*a(n-5) +73*a(n-6) +15*a(n-7) -7*a(n-8) +4*a(n-9) -30*a(n-10) -9*a(n-11) +8*a(n-12) for n>13

Example

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

Crossrefs

Cf. A302965.

Sequence in context: A302070 A302267 A113154 * A337367 A334323 A270161

Adjacent sequences: A302963 A302964 A302965 * A302967 A302968 A302969

Keyword

nonn

Author

R. H. Hardin, Apr 16 2018

Status

approved