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 A292909 #19 Sep 27 2017 18:51:00
%S A292909 1,0,1,-3,9,-40,210,-1176,7273,-49932,372060,-2971540,25359411,
%T A292909 -230364498,2215550428,-22460391240,239236043985,-2669869110856,
%U A292909 31134833803728,-378485082644400,4786085290280275,-62838103267148790,855122923978737876
%N A292909 E.g.f.: exp(1/2! * x^2 * exp(-x)).
%H A292909 Seiichi Manyama, <a href="/A292909/b292909.txt">Table of n, a(n) for n = 0..530</a>
%F A292909 a(n) = (-1)^n * A133189(n).
%o A292909 (PARI) x='x+O('x^66); Vec(serlaplace(exp(1/2!*x^2*exp(-x))))
%Y A292909 Column k=2 of A292948.
%Y A292909 Cf. A133189, A292907.
%K A292909 sign
%O A292909 0,4
%A A292909 _Seiichi Manyama_, Sep 26 2017