

A281003


a(n) is the number of unlabeled simple graphs with n vertices that have no automorphisms of odd parity.


0



1, 0, 0, 1, 6, 28, 252, 4726, 150324, 8308928, 817860888, 144938364368, 46784208920560, 27789645300385184, 30630702203393521120, 63070163901389334212336, 243902725979609232729020320, 1779250465648201682685291759744
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OFFSET

1,5


LINKS

Table of n, a(n) for n=1..18.
Brendan McKay, Isoclasses of simple graphs


MATHEMATICA

(* This assumes you have Brendan McKay's files listing isoclasses of simple graphs (see link), and starts from a(2), as there is no graph1.g6 *)
Table[
Length@ Select[
Import["graph" <> ToString[i] <> ".g6"],
Function[g,
! AnyTrue[GroupElements[GraphAutomorphismGroup[g]],
Apply[Times, (1)^(Length /@ First[#]  1)] == 1 &]
]
],
{i, 2, 9}
]


CROSSREFS

Sequence in context: A216413 A090898 A134872 * A049603 A035527 A220437
Adjacent sequences: A281000 A281001 A281002 * A281004 A281005 A281006


KEYWORD

nonn


AUTHOR

Mariano SuárezÁlvarez, Jan 12 2017


EXTENSIONS

More terms from Ira M. Gessel, May 30 2019


STATUS

approved



