A316878 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 4, 5, 6 or 7 king-move adjacent elements, with upper left element zero.

4, 14, 37, 105, 388, 1280, 4121, 13933, 46641, 154593, 516270, 1725502, 5753200, 19197252, 64095188, 213911810, 713904833, 2382943651, 7953695202, 26546786860, 88606850547, 295748963969, 987132925969, 3294803783913, 10997255560702

Offset

1,1

Comments

Column 3 of A316883.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +4*a(n-2) +14*a(n-3) -19*a(n-4) -63*a(n-5) -93*a(n-6) +71*a(n-7) +279*a(n-8) +285*a(n-9) -86*a(n-10) -418*a(n-11) -276*a(n-12) +28*a(n-13) +90*a(n-14) -9*a(n-15) for n>17

Example

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

Crossrefs

Cf. A316883.

Sequence in context: A209399 A192974 A187428 * A036368 A006071 A086954

Adjacent sequences: A316875 A316876 A316877 * A316879 A316880 A316881

Keyword

nonn

Author

R. H. Hardin, Jul 15 2018

Status

approved