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 A098874 #5 Feb 05 2014 20:18:04
%S A098874 3,18,12,108,24,72,168,384,360,456,720,1824,1368,3192,19260,6840,
%T A098874 13680,21000,80940,9576,50616,39120,220248,167808,264264,193800,
%U A098874 242820,181944,117360,424080,456456,848160,124488,2756520,1618344,3269112,2229840
%N A098874 Where A098018(k)=-n.
%C A098874 k is the first occurrence of -n in A098018.
%t A098874 f[n_] := Plus @@ MoebiusMu[ Drop[ Divisors[n], 1] - 1]; s = Table[0, {100}]; Do[ a = f[n]; If[ !Positive[a] && a > -101 && s[[ -a]] == 0, s[[ -a]] = n], {n, }]; s
%Y A098874 Cf. A098018, A098869.
%K A098874 nonn
%O A098874 1,1
%A A098874 _Leroy Quet_ and _Robert G. Wilson v_, Nov 03 2004