A299723 Number of nX3 0..1 arrays with every element equal to 1, 2, 3, 4, 5, 6 or 7 king-move adjacent elements, with upper left element zero.

1, 18, 141, 1027, 7664, 57471, 430401, 3222716, 24132103, 180705499, 1353151672, 10132613337, 75874616631, 568161175962, 4254481072055, 31858229585461, 238559480074272, 1786371253979085, 13376631505148125, 100166340017987924

Offset

1,2

Comments

Column 3 of A299728.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +8*a(n-2) +20*a(n-3) +25*a(n-4) +11*a(n-5) +2*a(n-6) for n>7

Example

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

Crossrefs

Cf. A299728.

Sequence in context: A204273 A081074 A299062 * A125355 A299834 A231951

Adjacent sequences: A299720 A299721 A299722 * A299724 A299725 A299726

Keyword

nonn

Author

R. H. Hardin, Feb 17 2018

Status

approved