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 A359986 #8 Oct 15 2024 15:07:19 %S A359986 1,2,5,16,67,374,2795,27472,343129,5242178,94775045,1976279584, %T A359986 46619596363,1225918376726,35526110971595,1124201803439968, %U A359986 38555828073355441,1424165085382532162,56356111920073052165,2378150844047351691376,106590791633357076443347 %N A359986 Number of quasi series-parallel matroids on [n]. %C A359986 A quasi series-parallel matroid is a collection of series-parallel matroids. See the Ferroni/Larson reference for a precise definition. %H A359986 Andrew Howroyd, <a href="/A359986/b359986.txt">Table of n, a(n) for n = 0..200</a> %H A359986 Luis Ferroni and Matt Larson, <a href="https://arxiv.org/abs/2303.02253">Kazhdan-Lusztig polynomials of braid matroids</a>, arXiv:2303.02253 [math.CO], 2023. %o A359986 (PARI) seq(n)=Vec(serlaplace( exp(2*x + intformal(serreverse(2*log(1 + x + O(x^n)) - x))) )) %o A359986 (PARI) seq(n) = Vec(serlaplace( exp(2*x + intformal(-x + 2*serreverse(1 + 2*x - exp(x + O(x^n))))) )) %Y A359986 Row sums of A359985. %K A359986 nonn %O A359986 0,2 %A A359986 _Andrew Howroyd_, Mar 08 2023