A317226 Number of nX4 0..1 arrays with every element unequal to 0, 1, 2, 3, 6, 7 or 8 king-move adjacent elements, with upper left element zero.

8, 49, 150, 490, 2306, 7988, 29512, 118116, 442877, 1674170, 6450674, 24532556, 93346024, 356756541, 1360006032, 5183724970, 19777793656, 75422946136, 287601611955, 1096920574964, 4183314671482, 15953394700394, 60842416445008

Offset

1,1

Comments

Column 4 of A317230.

Links

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

Formula

Empirical: a(n) = 7*a(n-1) -15*a(n-2) +27*a(n-3) -109*a(n-4) +212*a(n-5) -152*a(n-6) +262*a(n-7) -585*a(n-8) +224*a(n-9) +232*a(n-10) +159*a(n-11) -87*a(n-12) -588*a(n-13) +449*a(n-14) -47*a(n-15) +166*a(n-16) -212*a(n-17) +58*a(n-18) -10*a(n-19) +14*a(n-20) -4*a(n-21) for n>25

Example

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

Crossrefs

Cf. A317230.

Sequence in context: A316285 A018200 A306049 * A329051 A295777 A319959

Adjacent sequences: A317223 A317224 A317225 * A317227 A317228 A317229

Keyword

nonn

Author

R. H. Hardin, Jul 24 2018

Status

approved