A220730 Number of ways to reciprocally link elements of an 6Xn array either to themselves or to exactly two horizontal, diagonal or antidiagonal neighbors

1, 32, 2275, 331589, 42378036, 5717794568, 759141297226, 101519188093819, 13544010607777037, 1808631116741400544, 241439736338645879892, 32234631644593961566460, 4303448709056159145198981

Offset

1,2

Comments

Row 6 of A220725

Links

R. H. Hardin, Table of n, a(n) for n = 1..41

Example

Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10)
.69.46.47...69.47.00...00.79.00...00.00.00...00.67.47...00.79.00...00.00.00
.00.13.00...36.14.00...36.47.17...00.67.47...39.37.00...39.67.14...69.46.47
.00.67.47...00.79.00...39.37.00...39.37.00...36.14.00...36.14.00...00.13.00
.39.39.00...39.00.17...39.19.00...39.17.00...00.69.47...00.00.00...69.46.47
.00.16.14...00.13.00...00.16.14...39.16.47...00.39.17...00.00.00...00.13.00
.00.00.00...00.00.00...00.00.00...00.13.00...00.36.14...00.00.00...00.00.00

Crossrefs

Sequence in context: A321663 A264145 A180954 * A254458 A185968 A247999

Adjacent sequences: A220727 A220728 A220729 * A220731 A220732 A220733

Keyword

nonn

Author

R. H. Hardin Dec 18 2012

Status

approved