A298624 Number of nX3 0..1 arrays with every element equal to 2, 3, 4, 5 or 7 king-move adjacent elements, with upper left element zero.

0, 3, 8, 26, 138, 611, 2880, 13727, 65070, 310816, 1482870, 7081007, 33819984, 161533363, 771590878, 3685656306, 17605479026, 84097488439, 401715732434, 1918912755293, 9166251659440, 43785309700922, 209153493108094

Offset

1,2

Comments

Column 3 of A298629.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) +5*a(n-2) -27*a(n-3) -26*a(n-4) +79*a(n-5) +33*a(n-6) -168*a(n-7) +31*a(n-8) +142*a(n-9) -40*a(n-10) -8*a(n-11) for n>12

Example

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

Crossrefs

Cf. A298629.

Sequence in context: A058802 A054097 A238243 * A088590 A023637 A128894

Adjacent sequences: A298621 A298622 A298623 * A298625 A298626 A298627

Keyword

nonn

Author

R. H. Hardin, Jan 23 2018

Status

approved