login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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

%I

%S 1,0,4,12,56,280,1488,8232,47008,274824,1636520,9890584,60510480,

%T 374019776,2332131872,14651535840,92653845120,589317728376,

%U 3767523372432,24196006128592,156030800105840

%N Cycle class sequence c(2n) (the number of true cycles of length 2n in which a certain node is included) for square lattice.

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

%H G. Thimm, <a href="/thimm1.html">Cycle sequences of crystal structures</a>

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

%K nonn,more

%O 0,3

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

%E a(11) from _Gabriel B. Apolinario_, Jan 07 2017

%E a(12)-a(18) from _Aleksandr D. Krotov_, Jan 07 2018

%E a(19)-a(20) from _Aleksandr D. Krotov_, Mar 22 2019

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 3 13:43 EST 2021. Contains 349463 sequences. (Running on oeis4.)