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 A368851 #13 Jun 09 2025 21:01:23
%S A368851 1,6,108,12630,30263484,27712501015350,7560818318577145967460876,
%T A368851 469290709294376894968630603296687409248422837718
%N A368851 Number of (undirected) paths in the n-Dorogovtsev-Goltsev-Mendes graph.
%C A368851 Using the convention that DGM(0) = P_2.
%H A368851 Andrew Howroyd, <a href="/A368851/b368851.txt">Table of n, a(n) for n = 0..10</a>
%H A368851 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Dorogovtsev-Goltsev-MendesGraph.html">Dorogovtsev-Goltsev-Mendes Graph</a>.
%H A368851 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/GraphPath.html">Graph Path</a>.
%o A368851 (PARI)
%o A368851 step(S)={my([p,q,r,s,t]=S); [3*(p + q^2 + (2*q*r - r^2)*t + s*t^2), 2*(q + q*t + r*t^2), q + r + r*t, s + 4*q*r + r^2*(2*t - 1) + 2*s*t, t + t^2]}
%o A368851 a(n,x=1)={my(S=[x, x, 0, 0, x]); for(i=1, n, S=step(S)); S[1]} \\ _Andrew Howroyd_, Jun 09 2025
%Y A368851 Cf. A368190.
%K A368851 nonn
%O A368851 0,2
%A A368851 _Eric W. Weisstein_, Jan 07 2024
%E A368851 a(5) onwards from _Andrew Howroyd_, Jun 08 2025