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A220680 Number of ways to reciprocally link elements of an nX7 array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without consecutive collinear links 1
1, 441, 22000, 2316754, 215926776, 21051034046, 2045717834201, 198460804181024, 19267871745544463, 1870273847823355410, 181541549823743511322, 17622155633363587138681, 1710539337273283386055832 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Column 7 of A220681
LINKS
EXAMPLE
Some solutions for n=3 0=self 2=n 3=ne 4=w 6=e 7=sw 8=s (reciprocal directions total 10)
.00.00.00.00.78.00.00...00.78.00.67.48.68.47...00.00.00.00.68.48.00
.68.48.00.38.27.78.00...38.27.38.00.27.23.78...00.00.68.48.26.24.78
.26.24.00.23.36.24.00...23.00.26.34.00.36.24...00.00.26.24.00.36.24
CROSSREFS
Sequence in context: A264262 A232003 A221248 * A189278 A151656 A264088
KEYWORD
nonn
AUTHOR
R. H. Hardin Dec 17 2012
STATUS
approved

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Last modified June 19 12:43 EDT 2024. Contains 373503 sequences. (Running on oeis4.)