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A304305 Number of n X 3 0..1 arrays with every element unequal to 0, 1, 2, 3 or 5 king-move adjacent elements, with upper left element zero. 1
4, 23, 77, 261, 918, 3270, 11739, 42286, 152593, 551277, 1992676, 7204835, 26054060, 94223657, 340770353, 1232459982, 4457471732, 16121551990, 58307765439, 210885454206, 762723638858, 2758595178785, 9977203623515, 36085252551736 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 3 of A304310.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) +a(n-2) -6*a(n-3) -11*a(n-4) +2*a(n-5) +14*a(n-6) -6*a(n-7) -7*a(n-8) +15*a(n-9) +22*a(n-10) -6*a(n-11) -7*a(n-12) +a(n-13) +3*a(n-14) -10*a(n-15) -8*a(n-16).
EXAMPLE
Some solutions for n=5
..0..0..0. .0..0..0. .0..0..1. .0..1..0. .0..1..1. .0..1..1. .0..1..0
..1..1..1. .1..0..1. .0..0..0. .1..0..1. .0..0..1. .0..1..0. .1..1..1
..1..1..1. .0..0..0. .0..0..0. .1..1..0. .0..0..0. .1..0..0. .0..1..1
..0..1..1. .0..0..0. .0..1..1. .0..0..0. .0..0..0. .0..1..0. .0..0..1
..1..1..0. .0..0..1. .1..1..0. .0..0..1. .0..0..1. .1..0..1. .1..0..1
CROSSREFS
Cf. A304310.
Sequence in context: A226342 A071246 A219933 * A316204 A305771 A219465
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 10 2018
STATUS
approved

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Last modified July 23 07:34 EDT 2024. Contains 374546 sequences. (Running on oeis4.)