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 A112946 #7 Sep 01 2019 09:23:25
%S A112946 0,26,111096,513654400,2243178389200,9550256850912960,
%T A112946 40141310067406592352,167483578096089845880576,
%U A112946 695587719666862982630642400,2880023438585172541459822939200
%N A112946 Number of unrooted regular odd-valent planar maps with 6 vertices; maps are considered up to orientation-preserving homeomorphisms and the vertices are of valency 2n+1.
%C A112946 There is a closed formula.
%H A112946 Z. C. Gao, V. A. Liskovets and N. C. Wormald, <a href="http://mathstat.carleton.ca/~zgao/PAPER/poles.pdf">Enumeration of unrooted odd-valent regular planar maps</a>, Preprint, 2005.
%t A112946 a[n_] := With[{b = Binomial[2n, n]}, (1/120)(36n-1) n^2 b^6 + (3n^2 b^3)/4 + n b^2/3 + (4/5) Boole[Divisible[2n+1, 5]] Binomial[2 Floor[n/5], Floor[n/5]] b];
%t A112946 a /@ Range[0, 9] (* _Jean-François Alcover_, Sep 01 2019 *)
%Y A112946 Cf. A112945, A112947.
%K A112946 nonn
%O A112946 0,2
%A A112946 _Valery A. Liskovets_, Oct 10 2005