A306131 Number of nX3 0..1 arrays with every element unequal to 0, 2, 3, 4, 6 or 7 king-move adjacent elements, with upper left element zero.

1, 8, 13, 64, 240, 842, 3302, 12740, 48468, 187112, 723138, 2786916, 10760740, 41576054, 160572130, 620281406, 2396512260, 9258772148, 35771455196, 138208433662, 533989093282, 2063152495586, 7971370390066, 30798897460570

Offset

1,2

Comments

Column 3 of A306136.

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) +2*a(n-3) -29*a(n-4) -18*a(n-5) +80*a(n-6) -17*a(n-7) +7*a(n-8) +102*a(n-9) -112*a(n-10) -65*a(n-11) +61*a(n-12) -71*a(n-13) +49*a(n-14) +68*a(n-15) -72*a(n-16) -14*a(n-17) -16*a(n-19) -4*a(n-20)

Example

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

Crossrefs

Cf. A306136.

Sequence in context: A377561 A166670 A107764 * A177183 A228799 A329499

Adjacent sequences: A306128 A306129 A306130 * A306132 A306133 A306134

Keyword

nonn

Author

R. H. Hardin, Jun 22 2018

Status

approved