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A220744 Number of ways to reciprocally link elements of an 7Xn array either to themselves or to exactly two horizontal, diagonal and antidiagonal neighbors, without consecutive collinear links 0
1, 64, 3403, 355883, 32924133, 3287610473, 319803318494, 31411054258761, 3063698245151388 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row 7 of A220738

LINKS

Table of n, a(n) for n=1..9.

EXAMPLE

Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10)

.00.00.00...00.79.00...00.69.47...00.67.47...00.00.00...69.49.00...00.67.47

.00.00.00...39.69.14...00.36.14...39.39.00...00.67.47...00.17.17...36.34.00

.00.79.00...00.16.14...00.69.47...00.17.17...36.34.00...36.34.00...00.00.00

.39.79.17...69.47.00...00.36.14...36.34.00...69.49.00...69.47.00...00.69.47

.39.13.17...36.14.00...00.79.00...69.47.00...69.14.17...36.14.00...00.36.14

.00.13.00...69.47.00...39.69.14...39.17.00...00.13.00...69.47.00...00.00.00

.00.00.00...36.14.00...00.16.14...36.14.00...00.00.00...36.14.00...00.00.00

CROSSREFS

Sequence in context: A299179 A299941 A017439 * A298194 A299088 A299344

Adjacent sequences:  A220741 A220742 A220743 * A220745 A220746 A220747

KEYWORD

nonn

AUTHOR

R. H. Hardin Dec 18 2012

STATUS

approved

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Last modified May 26 07:29 EDT 2022. Contains 354077 sequences. (Running on oeis4.)