A220679 Number of ways to reciprocally link elements of an nX6 array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without consecutive collinear links

1, 169, 4604, 220299, 9973284, 455249977, 21051034046, 969333059888, 44710643494095, 2061425679292684, 95053260696179636, 4382893797173364311, 202094068495963167552, 9318534371184411614287, 429675728242919953910812

Offset

1,2

Comments

Column 6 of A220681

Links

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

Example

Some solutions for n=3 0=self 2=n 3=ne 4=w 6=e 7=sw 8=s (reciprocal directions total 10)
.00.78.00.00.67.48...00.68.47.78.68.47...00.00.68.47.67.48...00.78.78.00.00.00
.36.24.68.34.78.27...00.23.38.27.23.78...68.47.23.38.67.24...38.23.27.78.00.78
.00.00.26.34.23.00...00.00.23.00.36.24...23.00.00.23.00.00...26.34.36.24.36.24

Crossrefs

Sequence in context: A156160 A264261 A232002 * A201092 A264363 A232313

Adjacent sequences: A220676 A220677 A220678 * A220680 A220681 A220682

Keyword

nonn

Author

R. H. Hardin Dec 17 2012

Status

approved