A297810 Number of nX4 0..1 arrays with every element equal to 2 or 3 king-move adjacent elements, with upper left element zero.

0, 1, 2, 8, 13, 27, 41, 100, 208, 450, 898, 1871, 3889, 8201, 17095, 35607, 74032, 154537, 322580, 673283, 1403752, 2927384, 6106043, 12739513, 26576048, 55436430, 115633960, 241213607, 503185198, 1049671378, 2189629220, 4567589342

Offset

1,3

Comments

Column 4 of A297814.

Links

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

Formula

Empirical: a(n) = a(n-1) +2*a(n-2) +3*a(n-4) +2*a(n-5) -4*a(n-6) -11*a(n-7) -11*a(n-8) -6*a(n-9) +a(n-10) +6*a(n-11) +5*a(n-12) -a(n-14) for n>21

Example

Some solutions for n=7
..0..0..0..0. .0..0..1..1. .0..0..1..1. .0..0..1..1. .0..0..1..1
..0..1..1..0. .0..1..0..1. .0..1..0..1. .0..1..0..1. .0..1..0..1
..1..0..1..0. .1..1..0..1. .0..1..1..0. .0..1..0..1. .0..1..0..0
..1..0..1..0. .1..0..0..1. .1..0..0..0. .0..1..0..1. .0..1..1..0
..0..1..0..1. .1..0..1..1. .0..1..1..1. .0..1..0..1. .0..0..1..0
..0..1..0..1. .1..0..1..0. .1..0..0..1. .1..0..0..1. .1..0..1..0
..0..0..1..1. .1..1..0..0. .1..1..0..0. .1..1..1..1. .1..1..0..0

Crossrefs

Cf. A297814.

Sequence in context: A196024 A371381 A037382 * A298142 A095825 A106359

Adjacent sequences: A297807 A297808 A297809 * A297811 A297812 A297813

Keyword

nonn

Author

R. H. Hardin, Jan 06 2018

Status

approved