The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A185344

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A185344

Number of not necessarily connected 4-regular simple graphs on n vertices with girth at least 4.
(history; published version)

#28 by Michel Marcus at Wed Mar 18 09:00:45 EDT 2020

STATUS

reviewed

approved

#27 by Joerg Arndt at Wed Mar 18 07:49:51 EDT 2020

STATUS

proposed

reviewed

#26 by Jean-François Alcover at Wed Mar 18 06:54:58 EDT 2020

STATUS

editing

proposed

#25 by Jean-François Alcover at Wed Mar 18 06:54:52 EDT 2020

MATHEMATICA

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[A033886[[# + 1]]&];

(* EulerTransform is defined in A005195 *)

a /@ Range[0, LengthEulerTransform[Rest @ A033886] - 1] (* Jean-François Alcover, Dec 04 2019 , updated Mar 18 2020 *)

STATUS

approved

editing

#24 by Susanna Cuyler at Wed Dec 04 21:03:06 EST 2019

STATUS

proposed

approved

#23 by Jean-François Alcover at Wed Dec 04 08:58:50 EST 2019

STATUS

editing

proposed

#22 by Jean-François Alcover at Wed Dec 04 08:58:46 EST 2019

MATHEMATICA

A033886 = Cases[Import["https://oeis.org/A033886/b033886.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[A033886[[# + 1]]&];

a /@ Range[0, Length[A033886] - 1] (* Jean-François Alcover, Dec 04 2019 *)

STATUS

approved

editing

#21 by Charles R Greathouse IV at Thu May 01 02:39:58 EDT 2014

AUTHOR

_Jason Kimberley, _, Nov 03 2011

Discussion

Thu May 01

02:39

OEIS Server: https://oeis.org/edit/global/2198

#20 by Joerg Arndt at Sat Jan 19 11:37:48 EST 2013

STATUS

proposed

approved

#19 by Jason Kimberley at Sat Jan 19 09:52:02 EST 2013

STATUS

editing

proposed