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 A049133 #18 Sep 27 2023 10:05:39
%S A049133 1,1,2,4,8,14,15,-31,-308,-1520,-6138,-22260,-74745,-234503,-684931,
%T A049133 -1828743,-4249668,-7308296,-592722,75389838,487028178,2286167634,
%U A049133 9278268220,34247910114,117081254935,371845391419,1086709633580,2836930639816,6075557104011
%N A049133 Revert transform of (x - 1)^2/(1 - x - x^3).
%H A049133 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A049133 Recurrence: 2*n*(2*n - 1)*(26*n^2 - 125*n + 156)*a(n) = 3*(182*n^4 - 1291*n^3 + 3244*n^2 - 3388*n + 1158)*a(n-1) - 3*(78*n^4 - 973*n^3 + 3964*n^2 - 6793*n + 4431)*a(n-2) - (n-3)*(1690*n^3 - 10179*n^2 + 19241*n - 12657)*a(n-3) - 31*(n-4)*(n-3)*(26*n^2 - 73*n + 57)*a(n-4). - _Vaclav Kotesovec_, Jan 02 2021
%F A049133 a(n+1) = (1/(n+1)) * Sum_{k=0..floor(n/3)} (-1)^k * binomial(n+1,k) * binomial(2*n-2*k,n-3*k). - _Seiichi Manyama_, Sep 27 2023
%t A049133 Rest[CoefficientList[InverseSeries[Series[x*(x - 1)^2/(1 - x - x^3), {x, 0, 40}], x], x]] (* _Vaclav Kotesovec_, Jan 02 2021 *)
%Y A049133 Cf. A049128.
%K A049133 sign
%O A049133 1,3
%A A049133 _Olivier Gérard_