A304422 Number of nX3 0..1 arrays with every element unequal to 1, 2, 3, 4 or 5 king-move adjacent elements, with upper left element zero.

1, 25, 124, 836, 5227, 33263, 210954, 1338995, 8497693, 53931843, 342283175, 2172337312, 13786969248, 87500479337, 555331175880, 3524468904668, 22368420155320, 141963579269696, 900987092575923, 5718211285108957

Offset

1,2

Comments

Column 3 of A304427.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +15*a(n-2) +7*a(n-3) -36*a(n-4) -72*a(n-5) -51*a(n-6) -29*a(n-7) -19*a(n-8) -4*a(n-9) for n>10

Example

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

Crossrefs

Cf. A304427.

Sequence in context: A075047 A360640 A172047 * A280390 A225388 A369563

Adjacent sequences: A304419 A304420 A304421 * A304423 A304424 A304425

Keyword

nonn

Author

R. H. Hardin, May 12 2018

Status

approved