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A305771 Number of n X 3 0..1 arrays with every element unequal to 0, 1, 2, 3, 5 or 7 king-move adjacent elements, with upper left element zero. 1
4, 23, 81, 292, 1096, 4172, 15953, 61111, 234288, 898583, 3447045, 13224257, 50735544, 194653051, 746816146, 2865285427, 10993168588, 42177249636, 161820597240, 620853918472, 2382018289657, 9139044147504, 35063597098216 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 3 of A305776.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) +a(n-2) -a(n-3) -20*a(n-4) -8*a(n-5) +26*a(n-6) +14*a(n-7) -12*a(n-8) +11*a(n-9) +23*a(n-10) -8*a(n-11) -24*a(n-12) -10*a(n-13) +7*a(n-14) -10*a(n-15) -8*a(n-16).
EXAMPLE
Some solutions for n=5
..0..0..1. .0..1..1. .0..1..1. .0..1..1. .0..1..1. .0..1..0. .0..0..1
..0..1..0. .1..0..1. .0..1..0. .1..0..0. .1..0..1. .1..1..1. .0..0..0
..0..0..0. .1..1..1. .1..0..0. .1..0..1. .0..1..0. .0..1..1. .0..0..1
..1..0..0. .0..0..1. .0..1..0. .0..1..1. .0..1..0. .0..0..1. .1..0..0
..0..0..0. .1..0..0. .0..1..1. .0..0..0. .1..0..1. .1..0..1. .0..0..1
CROSSREFS
Cf. A305776.
Sequence in context: A219933 A304305 A316204 * A219465 A317120 A220647
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 10 2018
STATUS
approved

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Last modified July 23 11:07 EDT 2024. Contains 374549 sequences. (Running on oeis4.)