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 A007164 M1784 #13 Nov 08 2017 08:51:09 %S A007164 1,2,7,31,167,999,6495,44619,319463,2356406,17775821,136405506, %T A007164 1060866006,8339982193,66147792753,528559162227,4250413757583, %U A007164 34368723106860,279254390054538,2278795583070154,18667432144042678,153452484745198722 %N A007164 Number of P-graphs with 2n edges. %D A007164 R. C. Read, On the enumeration of a class of plane multigraphs, Aequat. Math., 31 (1986), 47-63. %D A007164 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %F A007164 a(n) = (A003169(n) + 2 * A007165(n) + A007163(n)) / 4. - _Sean A. Irvine_, Nov 06 2017 %Y A007164 Cf. A003169, A007163, A007165. %K A007164 nonn %O A007164 1,2 %A A007164 _N. J. A. Sloane_ %E A007164 a(5), a(9), a(10) corrected and more terms from _Sean A. Irvine_, Nov 06 2017