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.

A157015 Number of graphs with n vertices having a bipartite connected component.

Original entry on oeis.org

0, 1, 2, 3, 8, 18, 60, 232, 1389, 14174, 291396, 12307993, 1031244083, 166112993730, 50667178220215, 29104660317374991, 31455540471012663839, 64032442292149795841796, 245999865227419158171980939, 1787823661072649054474456291897, 24639596830978183991220162941946112
Offset: 0

Views

Author

Tanya Khovanova, Feb 21 2009

Keywords

Programs

  • Mathematica
    cbs[g_] := Or @@ Map[BipartiteQ, Map[InduceSubgraph[g, # ] &, ConnectedComponents[g]]] Table[Count[Map[cbs, ListGraphs[n]], True], {n, 7}]
    (* from Eric W. Weisstein, May 02 2009: *) First do: <
    				

Formula

a(n) = A000088(n) - A157016(n).

Extensions

Incorrect comment deleted by N. J. A. Sloane, Feb 22 2009
Terms from a(8) onwards from Max Alekseyev, Feb 22 2009
Offset corrected by Max Alekseyev, Feb 24 2009
a(8) corrected by W. Edwin Clark, May 02 2009; confirmed by Eric W. Weisstein
Corrected by Max Alekseyev and Vladeta Jovovic, May 02 2009
a(18)-a(20) from Max Alekseyev, Jun 24 2013

A157051 Number of connected unlabeled non-bipartite graphs on n nodes.

Original entry on oeis.org

0, 0, 0, 1, 3, 16, 95, 809, 10935, 260350, 11712539, 1006674967, 164059617696, 50335905627489, 29003487431654737, 31397381142185989848, 63969560113210957966315, 245871831682083553779103249, 1787331725248899067681312999794, 24636021429399867654036551645873645, 645465483198722799426625560872826564232
Offset: 0

Views

Author

Max Alekseyev, Feb 22 2009

Keywords

Comments

Inverse Euler transform of A157016.

Programs

Formula

a(n) = A001349(n) - A005142(n).

Extensions

a(0) corrected, a(18)-a(20) added by Max Alekseyev, Jun 24 2013
Showing 1-2 of 2 results.