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 A005028 M1257 #21 Feb 23 2021 18:03:59 %S A005028 1,2,4,12,33,102,312,1010,3256,10836,36094,122544,417150,1437712, %T A005028 4970904,17333772,60638124,213435264,753520804,2672606464,9505230397, %U A005028 33928264990,121400935184,435660446342,1566809204928,5648450745204,20402191885146,73842311224632 %N A005028 Number of symmetric trivalent maps with n nodes. %D A005028 C. F. Earl and L. J. March, Architectural applications of graph theory, pp. 327-355 of R. J. Wilson and L. W. Beineke, editors, Applications of Graph Theory. Academic Press, NY, 1979. %D A005028 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A005028 Andrew Howroyd, <a href="/A005028/b005028.txt">Table of n, a(n) for n = 3..500</a> %H A005028 C. F. Earl and L. J. March, <a href="/A005500/a005500_1.pdf">Architectural applications of graph theory</a>, pp. 327-355 of R. J. Wilson and L. W. Beineke, editors, Applications of Graph Theory. Academic Press, NY, 1979. (Annotated scanned copy) %Y A005028 Antidiagonal sums of the array in A169809. %Y A005028 Cf. A005027. %K A005028 nonn %O A005028 3,2 %A A005028 _N. J. A. Sloane_ %E A005028 Terms a(11) and beyond from _Andrew Howroyd_, Feb 22 2021