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.

Showing 1-2 of 2 results.

A124059 Number of connected asymmetric graphs with n nodes.

Original entry on oeis.org

1, 0, 0, 0, 0, 8, 144, 3552, 131452, 7840396, 797524380, 143325597564
Offset: 1

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Author

Keywords

Comments

A graph possessing only a single automorphism is called an identity or asymmetric graph, |Aut(g)|=1. - Travis Hoppe, Apr 27 2014

Crossrefs

Cf. A003400 (not-necessarily connected simple asymmetric graphs).
Cf. A275867 (disconnected simple asymmetric graphs).
Cf. Values of |Aut(g)| for simple connected graphs, A124059, A241454, A241455, A241456, A241457, A241458, A241459, A241460, A241461, A241462, A241463, A241464, A241465, A241466, A241467, A241468, A241469, A241470, A241471.

Formula

Inverse WEIGH transform of A003400 (see Transforms link).
a(n) = A003400(n) - A275867(n).

Extensions

a(12) from Alois P. Heinz, Jun 11 2018

A003400 Number of asymmetric (not necessarily connected) graphs with n nodes.

Original entry on oeis.org

1, 0, 0, 0, 0, 8, 152, 3696, 135004, 7971848, 805364776, 144123121972
Offset: 1

Views

Author

Keywords

Comments

Number of simple graphs g on n nodes with |Aut(g)| = 1.

References

  • F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 220, Section P3.4.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Cf. A124059 (connected simple asymmetric graphs).
Cf. A275867 (disconnected simple asymmetric graphs).
Cf. A000088 (simple graphs).

Programs

  • nauty
    for n in {1..10}; do geng -q ${n} | countg -q -a1 | grep altogether | awk '{print $1}'; done # - Sean A. Irvine, Apr 22 2015

Formula

a(n) = A124059(n) + A275867(n).

Extensions

a(8) and a(9) from Eric W. Weisstein, Jun 09 2004
a(10) and a(11) from Zoran Maksimovic, Vladeta Jovovic, Jan 21 2005
a(12) from Sean A. Irvine, Apr 22 2015
Showing 1-2 of 2 results.