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A268637
Number of nX6 0..2 arrays with some element plus some horizontally or vertically adjacent neighbor totalling two exactly once.
1
240, 7128, 163878, 3440052, 68710116, 1328460312, 25093766490, 465757993812, 8527096170390, 154406753980596, 2770879234068744, 49351916066147196, 873425626212657504, 15373652306609086368, 269322517606253198046
OFFSET
1,1
COMMENTS
Column 6 of A268639.
LINKS
FORMULA
Empirical: a(n) = 60*a(n-1) -1482*a(n-2) +20016*a(n-3) -167163*a(n-4) +924894*a(n-5) -3537110*a(n-6) +9593166*a(n-7) -18693789*a(n-8) +26218062*a(n-9) -26188161*a(n-10) +18139608*a(n-11) -8262712*a(n-12) +2220864*a(n-13) -266256*a(n-14) for n>15
EXAMPLE
Some solutions for n=3
..0..0..1..2..2..2. .0..1..2..1..0..0. .1..1..0..0..0..1. .0..1..2..1..0..0
..0..1..2..2..2..2. .1..2..1..2..1..1. .0..0..0..0..0..0. .0..0..1..2..1..0
..1..0..2..2..2..1. .2..1..2..1..0..0. .0..0..0..1..0..0. .1..1..2..1..0..1
CROSSREFS
Cf. A268639.
Sequence in context: A145094 A239245 A218131 * A264317 A270174 A008340
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 09 2016
STATUS
approved