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 A201740 #18 Nov 11 2012 14:53:55
%S A201740 1,-1,-1,-1,4,39,-158,211,-186,-33722,55130,192039,-4032991
%N A201740 The value of the Mertens function at n^n.
%D A201740 Marc Deleglise and Joel Rivat, Computing the summation of the Mobius function, Experiment. Math. 5 (1996), no. 4, 291-295.
%F A201740 a(n) = A002321(n^n).
%t A201740 Table[Sum[MoebiusMu[k], {k, n^n}], {n, 7}]
%Y A201740 Cf. A002321, A000312, A084237.
%K A201740 sign,more
%O A201740 1,5
%A A201740 _Carl Najafi_, Dec 04 2011
%E A201740 a(9)-a(10) from _Max Alekseyev_, Dec 10 2011
%E A201740 a(11) from _Donovan Johnson_, Jun 21 2012
%E A201740 a(12)-a(13) from _Rikard Nordgren_, Nov 10 2012