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 A217361 #14 Mar 21 2022 06:33:11
%S A217361 1,-1,0,5,-16,14,96,-495,880,2002,-17888,48178,19040,-665380,2501312,
%T A217361 -1983543,-23639952,124654250,-216770400,-722621130,5941209120,
%U A217361 -15657865020,-12958545600,267306817050,-972419359392,534946077108,11045425672512
%N A217361 Series reversion of x+x^2+2*x^3.
%H A217361 R. J. Mathar, <a href="/A217361/b217361.txt">Table of n, a(n) for n = 1..103</a>
%H A217361 Elżbieta Liszewska, Wojciech Młotkowski, <a href="https://arxiv.org/abs/1907.10725">Some relatives of the Catalan sequence</a>, arXiv:1907.10725 [math.CO], 2019.
%F A217361 D-finite with recurrence 7*n*(n-1)*a(n) +16*(n-1)*(2*n-3)*a(n-1) +12*(3*n-5)*(3*n-7)*a(n-2)=0.
%F A217361 Lim sup n->infinity |a(n)|^(1/n) = 6*sqrt(3/7) = 3.927922... - _Vaclav Kotesovec_, Sep 10 2013
%e A217361 If y=x+x^2+2*x^3, then x= y -y^2 +5*y^4 -16*y^5 +14*y^6 +96*y^7 -...
%t A217361 Rest[CoefficientList[InverseSeries[Series[x+x^2+2*x^3,{x,0,20}],x],x]] (* _Vaclav Kotesovec_, Sep 10 2013 *)
%Y A217361 Cf. A103779 (x+x^2+x^3), A006013 (x-2*x^2+x^3).
%K A217361 sign,easy
%O A217361 1,4
%A A217361 _R. J. Mathar_, Oct 01 2012