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 A049186 #17 Jul 27 2023 13:16:56
%S A049186 1,1,3,11,45,197,901,4259,20643,102035,512365,2606421,13403715,
%T A049186 69568071,363946211,1917148173,10160087333,54132552109,289790960735,
%U A049186 1557980372127,8408281616305,45536927325809,247397689058521
%N A049186 Revert transform of 2*x*(1-x-x^3-x^5+x^6)-x/(1+x).
%C A049186 Sign diagram of generating sequence: +++-+-++--------...
%C A049186 2*x*(1-x-x^3-x^5+x^6)-x/(1+x) = x -x^2 -x^3 -x^4 -x^5 -x^6 +x^7 +x^8 -x^9 +x^10-+... = y <-> x= y +y^2 +3*y^3 +11*y^4 +45*y^5+... - _R. J. Mathar_, Jul 21 2023
%H A049186 <a href="/index/Res#revert">Index entries for reversions of series</a>
%p A049186 Order := 80:
%p A049186 g := 2*x*(1-x-x^3-x^5+x^6)-x/(1+x) ;
%p A049186 solve(series(g, x)=y, x) :
%p A049186 convert(%, polynom) :
%p A049186 seq(coeff(%, y, i), i=0..Order-1) ; # _R. J. Mathar_, Jul 24 2023
%o A049186 (PARI) my(x='x+O('x^40)); Vec(serreverse(2*x*(1-x-x^3-x^5+x^6)-x/(1+x))) \\ _Michel Marcus_, Jul 21 2023
%Y A049186 Cf. A049189.
%K A049186 nonn
%O A049186 1,3
%A A049186 _Olivier Gérard_
%E A049186 NAME corrected by _R. J. Mathar_, Jul 21 2023