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 A256331 #15 Oct 06 2019 09:04:02 %S A256331 1,3,14,81,527,3684,27022,205149,1598303,12705939,102653652,840419676, %T A256331 6956988612,58132229976,489673597926,4153635860373,35449185841679, %U A256331 304179698619129,2622657870000646,22710277017073785,197418128701387895 %N A256331 Number of Largest Hairpin Family matchings on n edges. %C A256331 The Largest Hairpin Family of matchings is the largest family of matchings formed by repeated edge inflations and vertex insertions into the single edge and the hairpin. %H A256331 Aziza Jefferson, <a href="http://ufdc.ufl.edu/UFE0047620">The Substitution Decomposition of Matchings and RNA Secondary Structures</a>, PhD Thesis, University of Florida, 2015. %F A256331 G.f. f satisfies x*f^3 - (2*x+2)*f^2 + 5*f - 3 = 0. %e A256331 a(3) = 14 because of the 15 matchings on 3 edges, only 1 does not lie in the Largest Hairpin Family. In canonical sequence form, the missing matching is given by 121323. %p A256331 f := RootOf(_Z^3*x-2*_Z^2*x-2*_Z^2+5*_Z-3, 1); %p A256331 series(f, x=0, 30); %K A256331 nonn %O A256331 1,2 %A A256331 _Aziza Jefferson_, Mar 25 2015