A075545 Number of connected circulant graphs on n nodes.

1, 1, 1, 2, 2, 5, 3, 8, 6, 16, 7, 38, 13, 43, 40, 72, 35, 178, 59, 314, 195, 407, 187, 1256, 420, 1385, 920, 3054, 1181, 8702, 2191, 8280, 6759, 16423, 11138, 46552, 14601, 58227, 44409, 135784, 52487, 354951, 99879, 432158, 351374, 762419, 364723, 2121560, 798948, 3355968

Offset: 1

Author

Eric W. Weisstein, Sep 22 2002

Keywords

• nonn

Comments

Computed by Brendan McKay.

Links

• Jean-François Alcover, Table of n, a(n) for n = 1..70 [after _Andrew Howroyd_ for A049287 data]
• Eric Weisstein's World of Mathematics, Circulant Graph

Crossrefs

Cf. A049287.

Programs

Mathematica

CountDistinct /@ Table[Select[CanonicalGraph[CirculantGraph[n, #]] & /@ Subsets[Range[Floor[n/2]]], ConnectedGraphQ], {n, 25}] (* Eric W. Weisstein, May 13 2017 *)
A049287 = Cases[Import["https://oeis.org/A049287/b049287.txt", "Table"], {, }][[All, 2]];
a[n_] := Sum[MoebiusMu[n/d] A049287[[d]], {d, Divisors[n]}];
a /@ Range[70] (* Jean-François Alcover, Jan 11 2020 *)

Formula

Moebius transform of A049287. - Andrew Howroyd, Nov 04 2017

Extensions

a(1) changed to 1 by Andrew Howroyd, Apr 24 2017

a(41)-a(50) from Andrew Howroyd, Nov 04 2017