A220650 Number of ways to reciprocally link elements of an nX5 array either to themselves or to exactly two king-move neighbors, without 3-loops

1, 344, 59846, 8627817, 1233993907, 179768901595, 26120030149221, 3794284713986274, 551211422624758246, 80077716613058174101, 11633298013349256569296, 1690028849150702328710965

Offset

1,2

Comments

Column 5 of A220652

Links

R. H. Hardin, Table of n, a(n) for n = 1..136

Example

Some solutions for n=3 0=self 1=nw 2=n 3=ne 4=w 6=e 7=sw 8=s 9=se (reciprocal directions total 10)
.68.49.67.46.48...69.47.00.69.47...00.68.49.00.00...00.78.79.67.48
.28.39.17.78.27...36.14.68.34.18...68.24.78.17.00...38.23.37.18.28
.26.34.13.23.00...00.00.26.46.24...26.34.23.00.00...26.34.00.26.24

Crossrefs

Sequence in context: A185746 A202904 A086028 * A178191 A172934 A172952

Adjacent sequences: A220647 A220648 A220649 * A220651 A220652 A220653

Keyword

nonn

Author

R. H. Hardin Dec 17 2012

Status

approved