A077105 Number of nonisomorphic generalized Petersen P(n,k) graphs on 2n nodes for 1<=k<=floor((n-1)/2).

1, 1, 2, 2, 2, 3, 3, 4, 3, 5, 4, 5, 6, 6, 5, 7, 5, 8, 8, 8, 6, 11, 8, 10, 9, 11, 8, 13, 8, 12, 12, 13, 12, 15, 10, 14, 14, 17, 11, 18, 11, 17, 17, 17, 12, 21, 14, 20, 18, 20, 14, 22, 18, 23, 20, 22, 15, 27, 16, 23, 23, 24, 22, 28, 17, 26, 24, 29, 18, 31, 19, 28, 28, 29, 24, 33, 20

Offset: 3

Author

Eric W. Weisstein, Oct 28 2002

Keywords

• nonn

Comments

A generalized Petersen graph P(n,k) has 2n nodes and 3n edges and consists of an outer n-gon and an inner {n,k} star polygon for some k in the range 1<=k<=floor((n-1)/2); sequence gives number of nonisomorphic generalized Petersen graphs P(n,k) (for any k).

Examples

			The generalized Petersen graphs P(22,k) for k = 1, 2, 3, 4, 5, 6, 8, 10 are pairwise nonisomorphic, so a(22) = 8. - Arjana Zitnik (Arjana.Zitnik(AT)fmf.uni-lj.si)
		

Links

• Eric Weisstein's World of Mathematics, Generalized Petersen Graph

Programs

Mathematica

CountDistinct /@ Table[CanonicalGraph[PetersenGraph[n, k]], {n, 3, 79}, {k, (n - 1)/2}] (* Eric W. Weisstein, May 13 2017 *)

Extensions

My colleague Arjana Zitnik (Arjana.Zitnik(AT)fmf.uni-lj.si) found that a(22) was wrong. - Tomaz Pisanski, Nov 23 2004

Sequence corrected and extended by Eric W. Weisstein, Nov 28 2004