cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Previous Showing 11-13 of 13 results.

A275867 Number of simple disconnected asymmetric graph on n vertices.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 8, 144, 3552, 131452, 7840396, 797524408
Offset: 1

Views

Author

Eric W. Weisstein, May 19 2017

Keywords

Comments

For 2 < n < 12, a(n) = A124059(n-1) (connected asymmetric graphs). This is because the singleton is the only asymmetric graph with fewer than 6 vertices, so in a disconnected asymmetric graph with fewer than 12 vertices one connected component must be the singleton, and it cannot occur more than once. - Falk Hüffner, Jan 16 2020

References

  • 1

Crossrefs

Cf. A003400 (not-necessarily connected simple asymmetric graphs).
Cf. A124059 (connected simple asymmetric graphs).

Programs

  • Mathematica
    A[s_Integer] := With[{s6 = StringPadLeft[ToString[s], 6, "0"]}, Cases[ Import[ "https://oeis.org/A" <> s6 <> "/b" <> s6 <> ".txt", "Table"], {, }][[All, 2]]];
    A003400 = A@003400;
    A124059 = A@124059;
    a[n_] := A003400[[n]] - A124059[[n]];
    a /@ Range[12] (* Jean-François Alcover, Jan 07 2020 *)

Formula

a(n) = A003400(n) - A124059(n).

Extensions

a(12) from Jean-François Alcover, Jan 07 2020

A075094 Triangle of the sorted orders of graph automorphism groups for the simple graphs.

Original entry on oeis.org

1, 2, 2, 2, 2, 6, 6, 2, 2, 2, 4, 4, 6, 6, 8, 8, 24, 24, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4, 4, 4, 4, 4, 4, 6, 6, 8, 8, 8, 8, 10, 12, 12, 12, 12, 12, 12, 24, 24, 120, 120, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2
Offset: 1

Views

Author

Eric W. Weisstein, Aug 31 2002

Keywords

Comments

For n>1 row n ends with n!,n! since the automorphism group of the empty graph and the complete graph is the symmetric group. - Geoffrey Critzer, Aug 09 2016

Examples

			From _Geoffrey Critzer_, Aug 09 2016: (Start)
Triangle begins:
  1;
  2, 2;
  2, 2, 6, 6;
  2, 2, 2, 4, 4, 6, 6, 8, 8, 24, 24;
  ... (End)
		

Crossrefs

Cf. A003400, A000088 (row lengths).

Programs

  • Mathematica
    a = {1, 2, 4, 11, 34, 156, 1044};
    Table[Sort[Table[GraphData[{n, i}, "AutomorphismCount"], {i, 1, a[[n]]}]], {n,1, 7}] // Grid (* Geoffrey Critzer, Aug 09 2016 *)

A352765 Number of asymmetric n-node graphs with the smallest number (A352764(n)) of edges.

Original entry on oeis.org

1, 0, 0, 0, 0, 1, 2, 1, 1, 3, 6, 15, 29, 68, 144, 1, 3, 9, 24, 62
Offset: 1

Views

Author

Pontus von Brömssen, Apr 02 2022

Keywords

Crossrefs

Previous Showing 11-13 of 13 results.