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 A132962 #10 Sep 29 2017 02:49:27
%S A132962 1,0,2,-3,2,5,2,-140,282,819,2,-20482,2,133419,1527528,-4661085,2,
%T A132962 -153296429,2,1402482796,36278688162,13748957859,2,-14081800718427,
%U A132962 5194672859378,7905848380325,2977584150505252,12956452725792600,2,-1314647260913859151
%N A132962 a(n) = n!*Sum_{d|n} (-1)^(d+1)/(d!*(n/d)!^d).
%H A132962 G. C. Greubel, <a href="/A132962/b132962.txt">Table of n, a(n) for n = 1..500</a>
%F A132962 E.g.f.: Sum_{k>0}(1-exp(-x^k/k!)).
%t A132962 Rest[ Range[0, 30]! CoefficientList[ Series[ Sum[1 - Exp[ -x^k/k! ], {k, 30}], {x, 0, 30}], x]] (* _Robert G. Wilson v_, Sep 13 2007 *)
%o A132962 (PARI) a(n) = n!*sumdiv(n, d, (-1)^(d+1)/(d!*(n/d)!^d)); \\ _Michel Marcus_, Sep 29 2017
%Y A132962 Cf. A038041, A132958, A132959, A132960, A132961, A132963.
%K A132962 easy,sign
%O A132962 1,3
%A A132962 _Vladeta Jovovic_, Sep 06 2007
%E A132962 More terms from _Robert G. Wilson v_, Sep 13 2007