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 A380618 #6 Jan 28 2025 20:51:10
%S A380618 1,2,8,38,275,2614,30346,415360,6513999,115063118,2259975228,
%T A380618 48860184539,1153140907207,29502289676802,813371784160602,
%U A380618 24040797257734161,758379326971459945,25432414455826532993,903508909333199982128,33897272145242834426910,1339265974992611047296679
%N A380618 Number of sensed combinatorial maps with n edges and 2 vertices.
%C A380618 By duality, also the number of sensed combinatorial maps with n edges and 2 faces.
%H A380618 Andrew Howroyd, <a href="/A380618/b380618.txt">Table of n, a(n) for n = 1..200</a>
%o A380618 (PARI) \\ Needs G(), InvEulerMTS from A380615.
%o A380618 seq(n, k=2)={my(y='y); Vec(polcoef(InvEulerMTS(G(n, y*(1 + O(y^k)))), k, y))}
%Y A380618 Column 2 of A380615.
%Y A380618 Cf. A380237 (planar), A380619 (3 vertices), A380620 (unsensed).
%K A380618 nonn
%O A380618 1,2
%A A380618 _Andrew Howroyd_, Jan 28 2025