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A304422 Number of nX3 0..1 arrays with every element unequal to 1, 2, 3, 4 or 5 king-move adjacent elements, with upper left element zero. 1
1, 25, 124, 836, 5227, 33263, 210954, 1338995, 8497693, 53931843, 342283175, 2172337312, 13786969248, 87500479337, 555331175880, 3524468904668, 22368420155320, 141963579269696, 900987092575923, 5718211285108957 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Column 3 of A304427.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) +15*a(n-2) +7*a(n-3) -36*a(n-4) -72*a(n-5) -51*a(n-6) -29*a(n-7) -19*a(n-8) -4*a(n-9) for n>10
EXAMPLE
Some solutions for n=5
..0..0..1. .0..1..1. .0..1..1. .0..1..1. .0..1..0. .0..0..0. .0..1..1
..1..0..1. .0..0..0. .1..0..0. .1..0..0. .0..0..0. .1..0..1. .1..0..0
..1..0..0. .0..0..0. .1..1..0. .0..0..1. .1..0..1. .0..1..0. .1..0..0
..1..1..0. .1..0..1. .1..0..0. .0..1..0. .1..0..1. .1..1..1. .1..0..1
..1..0..0. .0..1..0. .0..1..1. .1..1..0. .0..1..0. .0..0..0. .0..1..1
CROSSREFS
Cf. A304427.
Sequence in context: A075047 A360640 A172047 * A280390 A225388 A369563
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 12 2018
STATUS
approved

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Last modified April 16 07:08 EDT 2024. Contains 371698 sequences. (Running on oeis4.)