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 A256336 #20 Oct 06 2019 09:04:37 %S A256336 1,3,14,81,521,3554,25172,183129,1359863,10264359,78521474,607449380, %T A256336 4744167924,37355679904,296232263792,2363773540473,18965408058723, %U A256336 152910824717297,1238260516988018,10066874219853977,82134185988563049,672294915226393926,5519252917557226452 %N A256336 Number of Largest Chain Ladder Family (LCLF) matchings on n edges. %C A256336 The Largest Chain Ladder Family (LCLF) of matchings is the largest family of matchings formed by repeated edge inflations by ladders and vertex insertions into a chain of any length. %H A256336 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 A256336 G.f. f satisfies 2x^3f^6-2x^2f^5+4x^2f^4-3xf^3+2xf^2+f-1=0. %e A256336 a(3)=14 because of the 15 matchings on 3 edges, only one does not lie in the Largest Chain Ladder Family. In canonical sequence form, the missing matching is given by 123123. %p A256336 f := RootOf(2*x^3*_Z^6-2*x^2*_Z^5+4*x^2*_Z^4-3*x*_Z^3+2*x*_Z^2+_Z-1,1); %p A256336 series(f, x=0, 30); %K A256336 nonn %O A256336 1,2 %A A256336 _Aziza Jefferson_, Mar 25 2015