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A297861
Number of nX3 0..1 arrays with every element equal to 2, 3 or 4 king-move adjacent elements, with upper left element zero.
1
0, 2, 4, 13, 62, 222, 820, 3159, 11882, 44870, 169628, 640493, 2419796, 9141186, 34529922, 130440579, 492746204, 1861372064, 7031443952, 26561657355, 100338117488, 379032792052, 1431817164232, 5408768126291, 20431919210138
OFFSET
1,2
COMMENTS
Column 3 of A297866.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) +4*a(n-2) -13*a(n-4) -8*a(n-5) -3*a(n-6) -4*a(n-7) +44*a(n-8) +33*a(n-9) -55*a(n-10) -42*a(n-11) +26*a(n-12) +16*a(n-13) -4*a(n-14) for n>16
EXAMPLE
Some solutions for n=7
..0..0..0. .0..0..1. .0..1..1. .0..0..1. .0..0..0. .0..0..1. .0..0..0
..0..1..0. .0..1..1. .0..0..1. .0..1..1. .0..1..0. .0..1..1. .0..1..0
..1..1..0. .0..1..1. .1..1..0. .1..0..0. .1..1..0. .1..0..0. .1..1..0
..1..0..0. .1..0..0. .1..0..0. .1..1..0. .1..0..0. .1..1..0. .0..0..1
..0..1..1. .0..1..0. .1..0..0. .0..1..1. .1..0..0. .1..0..0. .0..1..1
..0..0..1. .1..0..1. .1..0..1. .0..0..1. .0..1..1. .1..1..0. .0..1..1
..0..1..1. .1..1..1. .1..1..1. .0..1..1. .0..0..1. .1..0..0. .0..0..1
CROSSREFS
Cf. A297866.
Sequence in context: A020120 A020097 A139149 * A298128 A132786 A298065
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 07 2018
STATUS
approved