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A299684
Number of nX3 0..1 arrays with every element equal to 0, 1, 3, 4, 5, 6 or 7 king-move adjacent elements, with upper left element zero.
1
3, 4, 15, 54, 156, 854, 3226, 13013, 56318, 229915, 948257, 3968556, 16399773, 67970006, 282408197, 1170437914, 4854200458, 20140780494, 83525093575, 346439146067, 1437039382529, 5960289119226, 24721884651959, 102541799887631
OFFSET
1,1
COMMENTS
Column 3 of A299689.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +7*a(n-2) +20*a(n-3) -29*a(n-4) -87*a(n-5) -34*a(n-6) +86*a(n-7) +190*a(n-8) -8*a(n-9) -55*a(n-10) -38*a(n-11) +69*a(n-12) -71*a(n-13) -34*a(n-14) +30*a(n-15) for n>17
EXAMPLE
Some solutions for n=5
..0..1..0. .0..0..1. .0..1..1. .0..0..0. .0..0..1. .0..1..1. .0..1..1
..1..1..1. .0..0..1. .1..1..1. .0..0..0. .0..0..1. .1..1..1. .1..1..1
..1..1..0. .0..0..0. .0..1..1. .0..1..0. .1..1..1. .1..1..1. .0..1..0
..1..1..1. .1..1..0. .1..1..1. .0..0..0. .1..1..1. .0..0..0. .1..1..1
..0..1..1. .1..1..0. .1..1..1. .0..0..0. .0..1..0. .0..0..0. .1..1..0
CROSSREFS
Cf. A299689.
Sequence in context: A127144 A042771 A176755 * A211182 A135962 A171062
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 16 2018
STATUS
approved