OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..65
G. Thimm, Cycle sequences of crystal structures
G. Thimm and W. E. Klee, Zeolite cycle sequences, Zeolites, 19, pp. 422-424, 1997.
FORMULA
MATHEMATICA
(Length@FindCycle[{NearestNeighborGraph[Tuples[Range[2 # + 4], 2], {All, 1.}], {#+2, #+2}}, {2 #}, All]) & /@ Range[11] (* Gabriel B. Apolinario, Jan 07 2017 *)
CROSSREFS
KEYWORD
nonn
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
Terms a(21) and beyond added by Andrey Zabolotskiy, Jul 26 2022, using A002931
STATUS
approved