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A299583
Number of n X 3 0..1 arrays with every element equal to 1, 3, 4, 5, 7 or 8 king-move adjacent elements, with upper left element zero.
1
0, 4, 1, 8, 12, 31, 117, 263, 689, 1977, 5034, 13497, 36675, 96801, 258990, 694840, 1851440, 4950051, 13241884, 35365083, 94528266, 252701451, 675271071, 1804830952, 4824041591, 12892622434, 34458237926, 92097864532, 246147029176
OFFSET
1,2
COMMENTS
Column 3 of A299588.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +3*a(n-2) +5*a(n-3) -19*a(n-4) -16*a(n-5) +10*a(n-6) +32*a(n-7) -30*a(n-9) +75*a(n-10) +16*a(n-11) -99*a(n-12) -51*a(n-13) +52*a(n-14) +25*a(n-15) -4*a(n-16) +a(n-17) -2*a(n-18) -a(n-19) for n>20.
EXAMPLE
Some solutions for n=7
..0..0..0. .0..0..0. .0..0..0. .0..1..0. .0..0..0. .0..0..0. .0..0..0
..0..0..0. .0..0..0. .0..0..0. .0..1..0. .0..0..0. .0..0..0. .0..0..0
..0..0..0. .0..0..0. .0..0..1. .0..0..0. .0..0..0. .0..0..0. .1..1..1
..0..1..0. .0..1..0. .1..1..0. .0..0..0. .1..1..1. .1..0..0. .1..1..1
..1..0..0. .0..0..1. .1..1..1. .0..0..0. .1..1..1. .0..1..1. .1..1..1
..1..1..0. .0..1..1. .1..1..1. .1..1..1. .0..0..0. .1..1..1. .1..0..1
..1..1..0. .0..1..1. .1..1..1. .1..1..1. .0..0..0. .1..1..1. .1..0..1
CROSSREFS
Cf. A299588.
Sequence in context: A125129 A324780 A280108 * A013611 A297194 A077910
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 13 2018
STATUS
approved