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.
%I A003083 M2691 #20 Aug 11 2020 10:07:02 %S A003083 1,3,7,27,106,681,5972,88963,2349727,117165818,11073706216, %T A003083 1968717966417,654366802299848,406048824479878828, %U A003083 470960717141418629512,1023512961811602818909395,4179821138595428450831985657,32171971054480183600023612728841 %N A003083 Sum a(n) x^n / n = log (1 + Sum g(n) x^n ), where g(n) is # graphs on n nodes (A000088). %D A003083 F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 91. %D A003083 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %F A003083 a(n) = Sum_{d|n} d * A001349(d). - _Andrey Zabolotskiy_, Aug 11 2020 %t A003083 nn=20;g=Sum[NumberOfGraphs[n]x^n,{n,1,nn}];Drop[Range[0,nn]CoefficientList[ Series[Log[1+g],{x,0,nn}],x],1] (* _Geoffrey Critzer_, Oct 20 2012 *) %Y A003083 Cf. A000088, A001349. %K A003083 nonn,easy %O A003083 1,2 %A A003083 _N. J. A. Sloane_