A304843 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 4 or 7 king-move adjacent elements, with upper left element zero.

4, 12, 25, 51, 165, 419, 1009, 2697, 7091, 18147, 46901, 122403, 317379, 820951, 2131357, 5532371, 14340367, 37190407, 96488757, 250257339, 649031555, 1683483587, 4366629269, 11325556739, 29375297911, 76192462975, 197622279245

Offset

1,1

Comments

Column 3 of A304848.

Links

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

Formula

Empirical: a(n) = a(n-1) +2*a(n-2) +8*a(n-3) +a(n-4) -9*a(n-5) -26*a(n-6) -6*a(n-7) +6*a(n-8) +16*a(n-9) +2*a(n-10) +6*a(n-11) for n>12

Example

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

Crossrefs

Cf. A304848.

Sequence in context: A000297 A078618 A246988 * A062883 A364373 A008176

Adjacent sequences: A304840 A304841 A304842 * A304844 A304845 A304846

Keyword

nonn

Author

R. H. Hardin, May 19 2018

Status

approved