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 A060535 #7 May 10 2013 12:44:44
%S A060535 1,10,15,30,165,430,1170,3180,7935,18610,40948,84570,164740,304690,
%T A060535 538630,915574,1504135,2398460,3725495,5653790,8404075,12261860,
%U A060535 17592335,24857870,34638440,47655326,64798470,87157890,116059590
%N A060535 Number of homeomorphically irreducible multigraphs (or series-reduced multigraphs or multigraphs without nodes of degree 2) on 5 labeled nodes.
%D A060535 I. P. Goulden and D. M. Jackson, Combinatorial Enumeration, Wiley, N.Y., 1983.
%H A060535 Vladeta Jovovic, <a href="/A060533/a060533.pdf">Generating functions for homeomorphically irreducible multigraphs on n labeled nodes</a>
%F A060535 G.f.: (5*x^18 - 20*x^17 + 30*x^16 + 58*x^15 - 745*x^14 + 2790*x^13 - 5270*x^12 + 5010*x^11 - 711*x^10 - 4380*x^9 + 6270*x^8 - 4470*x^7 + 1535*x^6 + 178*x^5 - 450*x^4 + 210*x^3 - 40*x^2 + 1)/(x - 1)^10. E.g.f. for homeomorphically irreducible multigraphs with n nodes and k edges is (1 + x*y)^( - 1/2)*exp(x*y/2 + x^2*y^2/4)*Sum_{k >= 0} 1/(1 - x)^binomial(k, 2)*exp( - x^2*y*k^2/(2*(1 + x*y)) - x^2*y*k/2)*y^k/k!.
%Y A060535 Cf. A003514, A060516, A060533-A060537.
%K A060535 easy,nonn
%O A060535 0,2
%A A060535 _Vladeta Jovovic_, Apr 01 2001