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A295981
Number of nX4 0..1 arrays with each 1 adjacent to 2 or 3 king-move neighboring 1s.
1
1, 28, 110, 518, 3851, 21577, 124879, 764482, 4511480, 26744446, 159677743, 948805027, 5641302561, 33572029290, 199666287160, 1187596390882, 7064536068265, 42020681155895, 249946802006641, 1486752105918248
OFFSET
1,2
COMMENTS
Column 4 of A295985.
LINKS
FORMULA
Empirical: a(n) = 6*a(n-1) +26*a(n-3) -179*a(n-4) +42*a(n-5) +130*a(n-6) +641*a(n-7) -279*a(n-8) -739*a(n-9) -401*a(n-10) -138*a(n-11) +816*a(n-12) +647*a(n-13) +2430*a(n-14) -801*a(n-15) -2367*a(n-16) +603*a(n-17) +742*a(n-18) -583*a(n-19) +1231*a(n-20) -74*a(n-21) -471*a(n-22) +479*a(n-23) +53*a(n-24) -161*a(n-25) +48*a(n-26) -4*a(n-27)
EXAMPLE
Some solutions for n=7
..0..0..1..0. .1..1..0..0. .0..0..0..0. .0..0..1..1. .0..0..1..1
..0..0..1..1. .1..0..1..1. .0..1..1..1. .1..1..0..1. .0..1..0..1
..0..0..0..1. .1..0..0..1. .1..0..1..0. .1..0..0..1. .1..0..0..0
..1..1..0..0. .1..1..1..0. .1..0..0..0. .0..0..1..0. .1..1..0..0
..1..0..0..1. .0..0..0..0. .1..0..1..1. .0..1..0..1. .1..0..0..0
..0..1..1..1. .0..0..1..0. .0..1..0..1. .1..0..0..1. .1..0..0..1
..0..0..0..0. .0..1..1..1. .0..0..1..0. .0..1..1..0. .1..1..1..1
CROSSREFS
Cf. A295985.
Sequence in context: A183341 A118613 A245153 * A064763 A219594 A042534
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 01 2017
STATUS
approved