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 A362278 #20 Apr 18 2023 16:42:36
%S A362278 1,1,-2,-8,10,106,-44,-1952,-1028,45820,73576,-1301024,-3729032,
%T A362278 43107832,188540080,-1621988864,-10106292464,67749173008,583170088672,
%U A362278 -3075285253760,-36315980308064,148201134917536,2436107894325568,-7345167010231808
%N A362278 Expansion of e.g.f. exp(x - 3*x^2/2).
%H A362278 Winston de Greef, <a href="/A362278/b362278.txt">Table of n, a(n) for n = 0..690</a>
%F A362278 a(n) = a(n-1) - 3*(n-1)*a(n-2) for n > 1.
%F A362278 a(n) = n! * Sum_{k=0..floor(n/2)} (-3/2)^k / (k! * (n-2*k)!).
%t A362278 With[{nn=30},CoefficientList[Series[Exp[x-3 x^2/2],{x,0,nn}],x] Range[0,nn]!] (* _Harvey P. Dale_, Apr 18 2023 *)
%o A362278 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(x-3*x^2/2)))
%Y A362278 Column k=3 of A362277.
%Y A362278 Cf. A115327.
%K A362278 sign,easy
%O A362278 0,3
%A A362278 _Seiichi Manyama_, Apr 13 2023