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 A009206 #22 Dec 25 2021 12:05:39
%S A009206 0,1,2,3,0,-15,-48,-21,448,1953,640,-32461,-152064,77649,4331264,
%T A009206 18557595,-46686208,-894805183,-2948087808,21405607651,254321049600,
%U A009206 421226202033,-10904188190720,-90171090228021,96102216892416,6418365899545825
%N A009206 Expansion of e.g.f.: exp(sin(x))*x.
%F A009206 a(n) = n * A002017(n-1). - _Ralf Stephan_, Sep 01 2003
%F A009206 E.g.f.: x*E(0) -x, where E(k) = 2 + sin(x)/(2*k+1 - sin(x)/E(k+1) ); (continued fraction). - _Sergei N. Gladkovskii_, Dec 24 2013
%t A009206 With[{nn=30},CoefficientList[Series[Exp[Sin[x]]*x,{x,0,nn}],x] Range[ 0,nn]!] (* _Harvey P. Dale_, Dec 25 2021 *)
%K A009206 sign,easy
%O A009206 0,3
%A A009206 _R. H. Hardin_
%E A009206 Extended with signs by _Olivier Gérard_, Mar 15 1997
%E A009206 Definition clarified and prior Mathematica program replaced by _Harvey P. Dale_, Dec 25 2021