A278089 Number of n X 3 0..1 arrays with every element both equal and not equal to some elements at offset (-1,0) (-1,1) (0,-1) (0,1) or (1,0), with upper left element zero.

0, 3, 16, 66, 351, 1758, 9033, 46159, 236245, 1208622, 6183942, 31638994, 161877345, 828222749, 4237494527, 21680576851, 110925816281, 567537279930, 2903729582172, 14856548980595, 76011571374458, 388903168793624

Offset

1,2

Comments

Column 3 of A278094.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +14*a(n-2) -9*a(n-3) -44*a(n-4) +21*a(n-5) +83*a(n-6) -19*a(n-7) -81*a(n-8) +a(n-9) +17*a(n-10) -10*a(n-11) +4*a(n-12) +5*a(n-13) for n > 16.

Example

Some solutions for n=4
..0..1..1. .0..0..0. .0..0..1. .0..1..1. .0..1..1. .0..0..0. .0..1..1
..0..0..0. .1..1..1. .1..0..1. .0..1..0. .0..1..0. .1..1..1. .0..0..0
..1..1..1. .0..1..0. .1..0..0. .0..0..0. .0..1..0. .1..0..1. .1..0..1
..0..0..0. .0..1..0. .1..1..1. .1..1..1. .0..1..1. .0..0..1. .1..0..1

Crossrefs

Cf. A278094.

Sequence in context: A293579 A044046 A179600 * A248016 A000269 A370248

Adjacent sequences: A278086 A278087 A278088 * A278090 A278091 A278092

Keyword

nonn

Author

R. H. Hardin, Nov 11 2016

Status

approved