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A019266 Cycle class sequence c(2n) (the number of true cycles of length 2n in which a certain node is included) for square lattice. 0
1, 0, 4, 12, 56, 280, 1488, 8232, 47008, 274824, 1636520, 9890584, 60510480, 374019776, 2332131872, 14651535840, 92653845120, 589317728376, 3767523372432, 24196006128592, 156030800105840 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

REFERENCES

G. Thimm and W. E. Klee, Zeolite cycle sequences, Zeolites, 19, pp. 422-424, 1997.

LINKS

Table of n, a(n) for n=0..20.

G. Thimm, Cycle sequences of crystal structures

MATHEMATICA

(Length@FindCycle[{NearestNeighborGraph[Tuples[Range[2 # + 4], 2], {All, 1.}], {#+2, #+2}}, {2 #}, All]) &  /@ Range[11] (* Gabriel B. Apolinario, Jan 07 2017 *)

CROSSREFS

Sequence in context: A164575 A124004 A243785 * A009114 A144012 A197924

Adjacent sequences:  A019263 A019264 A019265 * A019267 A019268 A019269

KEYWORD

nonn,more

AUTHOR

Georg Thimm (mgeorg(AT)ntu.edu.sg)

EXTENSIONS

a(11) from Gabriel B. Apolinario, Jan 07 2017

a(12)-a(18) from Aleksandr D. Krotov, Jan 07 2018

a(19)-a(20) from Aleksandr D. Krotov, Mar 22 2019

STATUS

approved

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Last modified May 28 11:40 EDT 2020. Contains 334681 sequences. (Running on oeis4.)