A268637 Number of nX6 0..2 arrays with some element plus some horizontally or vertically adjacent neighbor totalling two exactly once.

240, 7128, 163878, 3440052, 68710116, 1328460312, 25093766490, 465757993812, 8527096170390, 154406753980596, 2770879234068744, 49351916066147196, 873425626212657504, 15373652306609086368, 269322517606253198046

Offset

1,1

Comments

Column 6 of A268639.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

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

Adjacent sequences: A268634 A268635 A268636 * A268638 A268639 A268640

Keyword

nonn

Author

R. H. Hardin, Feb 09 2016

Status

approved