|
| |
|
|
A069739
|
|
Size of the key space for isomorphism verification of circulant graphs of order n.
|
|
2
| |
|
|
1, 1, 1, 2, 1, 1, 1, 5, 2, 1, 1, 2, 1, 1, 1, 14, 1, 2, 1, 2, 1, 1, 1, 5, 2, 1, 5, 2, 1, 1, 1, 42, 1, 1, 1, 4, 1, 1, 1, 5, 1, 1, 1, 2, 2, 1, 1, 14, 2, 2, 1, 2, 1, 5, 1, 5, 1, 1, 1, 2, 1, 1, 2, 132, 1, 1, 1, 2, 1, 1, 1, 10, 1, 1, 2, 2, 1, 1, 1, 14, 14, 1, 1, 2, 1, 1, 1, 5, 1, 2
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,4
|
|
|
COMMENTS
| Multiplicative with a(p^m)=Catalan(m) (A000108). Coincides with A066060 up to n=63 except for n=32.
|
|
|
REFERENCES
| M. Muzychuk, A solution of the isomorphism problem for circulant graphs, Proc. London Math. Soc. (3) 88 (2004), no. 1, 1-41.
|
|
|
FORMULA
| a(n)=prod_p Catalan(m_p) where n=prod_p p^(m_p), p|n prime.
|
|
|
MAPLE
| A000108 := proc(n) binomial(2*n, n)/(n+1) ; end proc:
A069739 := proc(n) local ifa; if n = 1 then 1; else ifa := ifactors(n)[2] ; mul( A000108(op(2, f)), f=ifa) ; end if; end proc:
seq(A069739(n), n=1..90) ; # R. J. Mathar, Feb 08 2011
|
|
|
CROSSREFS
| Cf. A000108, A066060.
Sequence in context: A099940 A157249 A155586 * A066060 A008550 A064094
Adjacent sequences: A069736 A069737 A069738 * A069740 A069741 A069742
|
|
|
KEYWORD
| mult,easy,nonn
|
|
|
AUTHOR
| Valery Liskovets (liskov(AT)im.bas-net.by), Apr 15 2002
|
| |
|
|
