A220716 Number of ways to reciprocally link elements of an nX5 array either to themselves or to exactly two king-move neighbors, without consecutive collinear links

1, 463, 21195, 2126423, 168897201, 14158198781, 1166906554415, 96567512189416, 7981186640240601, 659847172787561616, 54547074666150602023, 4509337888390693628506, 372777382369854018831622

Offset

1,2

Comments

Column 5 of A220718

Links

R. H. Hardin, Table of n, a(n) for n = 1..129

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)
.00.68.49.79.00...00.00.00.68.48...89.00.68.49.00...00.69.48.00.78
.00.29.38.16.14...68.48.69.24.27...29.18.29.69.14...68.47.12.38.27
.00.00.12.00.00...26.24.00.13.00...00.12.00.16.14...23.00.00.23.00

Crossrefs

Sequence in context: A293025 A108834 A233310 * A189830 A111697 A116344

Adjacent sequences: A220713 A220714 A220715 * A220717 A220718 A220719

Keyword

nonn

Author

R. H. Hardin Dec 18 2012

Status

approved