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 A158206 #16 Feb 16 2025 08:33:09
%S A158206 1,1,1,1,2,1,3,2,3,3,6,2,8,6,7,7,15,7,20,11,18,20,36,14,44,35,45,37,
%T A158206 83,36,109,70,101,106,174,77,246,182,227
%N A158206 Number of irreducible numerical semigroups with Frobenius number n; that is, irreducible numerical semigroups for which the largest integer not belonging to them is n.
%H A158206 S. R. Finch, <a href="http://www.people.fas.harvard.edu/~sfinch/">Monoids of natural numbers</a>
%H A158206 S. R. Finch, <a href="/A066062/a066062.pdf">Monoids of natural numbers</a>, March 17, 2009. [Cached copy, with permission of the author]
%H A158206 Calvin Leng, Christopher O'Neill, <a href="https://arxiv.org/abs/1809.09915">A sequence of quasipolynomials arising from random numerical semigroups</a>, arXiv:1809.09915 [math.CO], 2018.
%H A158206 J. C. Rosales, P. A. Garcia-Sanchez, J. I. Garcia-Garcia and J. A. Jimenez-Madrid, <a href="https://doi.org/10.1016/j.jpaa.2003.10.024">Fundamental gaps in numerical semigroups</a>, Journal of Pure and Applied Algebra 189 (2004) 301-313.
%H A158206 Clayton Cristiano Silva, <a href="http://www.ime.unicamp.br/~ftorres/ENSINO/MONOGRAFIAS/Clayton.pdf">Irreducible Numerical Semigroups</a>, University of Campinas, São Paulo, Brazil (2019).
%H A158206 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/FrobeniusNumber.html">Frobenius number</a>
%H A158206 <a href="/index/Se#semigroups">Index entries for sequences related to semigroups</a>
%e A158206 a(5)=2: the 2 irreducible semigroups generated by {3, 4} and {2, 7} have Frobenius number 5.
%Y A158206 Cf. A124506.
%K A158206 nonn,more
%O A158206 1,5
%A A158206 _Steven Finch_, Mar 13 2009