A054917 Number of connected unlabeled vertex-transitive graphs with n nodes such that complement is also connected.

1, 0, 0, 0, 1, 2, 2, 6, 5, 14, 6, 54, 12, 46, 40, 258, 34, 350, 58, 1166, 230, 798, 186, 15338, 458, 4206, 1416, 25734, 1180, 46164, 2190, 676830, 6750, 132506, 11138, 1962310, 14600, 814094, 48432, 13101722, 52486, 9461632, 99878, 39133004, 399310, 34333422, 364722

Offset: 1

Author

N. J. A. Sloane, May 24 2000

Keywords

• nonn

Links

• V. A. Liskovets, Some easily derivable sequences, J. Integer Sequences, 3 (2000), #00.2.2.

Crossrefs

Cf. A006799, A006800.

Programs

Mathematica

nmax = 47;
A006799 = Cases[Import["https://oeis.org/A006799/b006799.txt", "Table"], {, }][[All, 2]];
A006800 = Table[Sum[MoebiusMu[n/d] A006799[[d]], {d, Divisors[n]}], {n, 1, nmax}];
a[n_] := 2*A006800[[n]] - A006799[[n]];
Array[a, nmax] (* Jean-François Alcover, Aug 27 2019, after Andrew Howroyd *)

Formula

a(n) = 2*A006800(n) - A006799(n).

Extensions

Missing a(1) inserted and a(32)-a(47) from Andrew Howroyd, Nov 27 2018