A300684 Number of nX3 0..1 arrays with every element equal to 1, 2, 3 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

1, 10, 53, 272, 1391, 7187, 37100, 191529, 988754, 5104580, 26353052, 136051331, 702383958, 3626156187, 18720542075, 96647438007, 498956024752, 2575930831916, 13298606130275, 68655929293704, 354445915677949, 1829877017719215

Offset

1,2

Comments

Column 3 of A300689.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) +3*a(n-2) -11*a(n-3) +a(n-4) -9*a(n-5) -3*a(n-6) +10*a(n-7) -2*a(n-8) -14*a(n-9) -8*a(n-10) -4*a(n-11) +8*a(n-13) +4*a(n-14) for n>15

Example

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

Crossrefs

Cf. A300689.

Sequence in context: A063899 A006889 A300422 * A300607 A301349 A007035

Adjacent sequences: A300681 A300682 A300683 * A300685 A300686 A300687

Keyword

nonn

Author

R. H. Hardin, Mar 11 2018

Status

approved