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A306162
Number of nX4 0..1 arrays with every element unequal to 0, 1, 2, 5, 6 or 7 king-move adjacent elements, with upper left element zero.
1
8, 9, 32, 103, 298, 962, 2966, 8756, 26287, 79873, 241656, 729008, 2201471, 6653034, 20101552, 60722489, 183440897, 554200361, 1674289991, 5058110361, 15280857422, 46164569525, 139466343261, 421337009501, 1272887195452, 3845478091572
OFFSET
1,1
COMMENTS
Column 4 of A306166.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +4*a(n-2) -a(n-4) -17*a(n-5) -22*a(n-6) +2*a(n-7) +38*a(n-8) +42*a(n-9) -5*a(n-10) -5*a(n-11) -9*a(n-12) -24*a(n-13) -26*a(n-14) -20*a(n-15) +6*a(n-16) +20*a(n-17) +16*a(n-18) for n>23
EXAMPLE
Some solutions for n=5
..0..0..0..0. .0..1..0..0. .0..0..1..1. .0..0..0..1. .0..0..1..1
..1..0..0..1. .0..0..0..0. .0..0..1..1. .0..0..1..0. .0..1..0..1
..0..0..0..0. .0..0..0..0. .1..1..1..1. .0..0..0..0. .1..0..1..1
..1..0..0..0. .0..0..0..1. .1..1..1..1. .1..0..0..1. .1..1..1..1
..0..0..1..0. .0..1..0..0. .1..1..1..1. .0..0..0..0. .1..1..1..1
CROSSREFS
Cf. A306166.
Sequence in context: A181900 A371443 A038344 * A050771 A120776 A041136
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 23 2018
STATUS
approved