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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.
1
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
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 24 2018
STATUS
approved