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A298778
Number of n X 4 0..1 arrays with every element equal to 0, 3, 4, 5 or 8 king-move adjacent elements, with upper left element zero.
1
1, 2, 2, 4, 11, 26, 76, 222, 721, 2361, 7737, 25780, 85449, 284610, 947298, 3154457, 10507280, 34994885, 116569493, 388281532, 1293363746, 4308190293, 14350558511, 47801810756, 159227933912, 530389181794, 1766729082040, 5884984209038
OFFSET
1,2
COMMENTS
Column 4 of A298782.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) +5*a(n-2) -8*a(n-3) -21*a(n-4) +8*a(n-5) +16*a(n-6) +19*a(n-7) +5*a(n-8) +10*a(n-9) -12*a(n-10) -43*a(n-11) -12*a(n-12) -3*a(n-13) +26*a(n-14) +11*a(n-15) +7*a(n-16) -3*a(n-17) -13*a(n-18) +7*a(n-19) +2*a(n-20) -3*a(n-21) for n>27.
EXAMPLE
Some solutions for n=5
..0..0..1..1. .0..0..1..1. .0..0..0..0. .0..0..1..1. .0..0..0..0
..0..0..1..1. .0..0..1..1. .0..0..0..0. .0..0..1..1. .0..0..0..0
..1..1..0..0. .0..0..1..0. .0..0..0..0. .1..0..0..1. .0..0..0..0
..1..1..0..0. .0..0..1..1. .0..0..0..0. .0..0..1..1. .1..1..1..1
..1..1..0..0. .0..0..1..1. .0..0..0..0. .0..0..1..1. .1..1..1..1
CROSSREFS
Cf. A298782.
Sequence in context: A052338 A153950 A153947 * A260878 A064880 A115011
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 26 2018
STATUS
approved