A343872 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A343872

Number of planar graphs with n edges and no isolated nodes.

1

1, 1, 2, 5, 11, 26, 68, 177, 497, 1475, 4608, 15188, 52778, 192339, 733676, 2917722, 12052138, 51517308, 227068741, 1028492568

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

COMMENTS

The first difference between this sequence and A000664 is for n=9 edges where we see K_{3,3}, the "utility graph".

LINKS

Table of n, a(n) for n=0..19.

FORMULA

Euler transform of A046091.

MATHEMATICA

A046091 = Cases[Import["https://oeis.org/A046091/b046091.txt", "Table"], {_, _}][[All, 2]];

etr[f_] := Module[{b}, b[n_] := b[n] = If[n == 0, 1, Sum[Sum[d f[d], {d, Divisors[j]}] b[n - j], {j, 1, n}]/n]; b];

a = etr[A046091[[# + 1]]&];

a /@ Range[0, Length[A046091]-1] (* Jean-François Alcover, Jan 01 2022 *)

CROSSREFS

Cf. A000664, A005470, A039735, A046091.

Sequence in context: A095892 A239311 A319760 * A000664 A364597 A242766

Adjacent sequences: A343869 A343870 A343871 * A343873 A343874 A343875

KEYWORD

nonn,more

AUTHOR

Andrew Howroyd, May 05 2021

STATUS

approved