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A305949
Number of nX3 0..1 arrays with every element unequal to 0, 2, 3, 4, 5 or 7 king-move adjacent elements, with upper left element zero.
2
1, 8, 23, 107, 537, 2800, 14652, 77128, 406622, 2146188, 11333438, 59863786, 316248100, 1670789296, 8827362224, 46638933714, 246416884814, 1301950664178, 6878911947762, 36345074634940, 192031153782354, 1014607291471240
OFFSET
1,2
COMMENTS
Column 3 of A305954.
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) +7*a(n-2) -13*a(n-3) -88*a(n-4) -25*a(n-5) +177*a(n-6) +214*a(n-7) +73*a(n-8) -188*a(n-9) -194*a(n-10) -92*a(n-11) -26*a(n-12) -26*a(n-13) -18*a(n-14) +16*a(n-15) +8*a(n-16) for n>17
EXAMPLE
Some solutions for n=5
..0..1..0. .0..0..1. .0..1..0. .0..1..1. .0..1..1. .0..1..0. .0..1..0
..0..1..1. .1..1..0. .0..1..0. .0..1..1. .1..0..0. .1..1..0. .1..0..1
..1..0..0. .0..1..1. .1..0..1. .0..0..0. .0..1..1. .0..1..1. .1..0..1
..1..0..1. .0..0..1. .0..0..1. .1..0..1. .1..1..0. .1..0..1. .0..0..1
..1..0..1. .1..1..0. .1..0..1. .0..1..0. .0..0..1. .0..1..0. .1..1..0
CROSSREFS
Cf. A305954.
Sequence in context: A320310 A303720 A304414 * A220973 A233470 A334720
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 15 2018
STATUS
approved