cp's OEIS Frontend

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.

A264761 Number of irreducible indecomposable spherical curves with n crossings (only ordinary double points), the circle is oriented, the sphere is oriented (OO case).

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%I A264761 #25 Mar 30 2024 12:15:17
%S A264761 0,0,1,1,2,6,17,73,290,1274,5844,27750,135192,676263,3437509,17811771,
%T A264761 93531354,497835030,2680058068,14577839412,80039070868,443164758244,
%U A264761 2472713506356
%N A264761 Number of irreducible indecomposable spherical curves with n crossings (only ordinary double points), the circle is oriented, the sphere is oriented (OO case).
%C A264761 Irreducible means not made disconnected by removal of a vertex (no nugatory crossings).
%C A264761 Indecomposable (or prime) means not made disconnected by cutting two distinct lines.
%H A264761 J. Betrema, <a href="https://github.com/j2b2/TaitCurves">Tait Curves</a>
%H A264761 R. Coquereaux and J.-B. Zuber, <a href="http://arxiv.org/abs/1507.03163">Maps, immersions and permutations</a>, arXiv preprint arXiv:1507.03163 [math.CO], 2015-2016. Also J. Knot Theory Ramifications 25, 1650047 (2016), DOI: <a href="https://doi.org/10.1142/S0218216516500474">10.1142/S0218216516500474</a>.
%o A264761 (C) See the J. Betrema C program in the Tait Curves link.
%Y A264761 Cf. A008986, A008987, A008988, A008989, A007756, A264759, A264760.
%K A264761 nonn,more
%O A264761 1,5
%A A264761 _Robert Coquereaux_, Nov 23 2015
%E A264761 a(15)-a(16) using J. Betrema's program added by _Andrey Zabolotskiy_, Aug 24 2023
%E A264761 a(17)-a(23) from _Brendan McKay_, Mar 30 2024