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 A215615 #11 Aug 18 2012 14:09:56
%S A215615 1,1,2,5,11,0,232,2295,26714,453871,7053157,0,7715707299,545539395584,
%T A215615 42297694603648,4883188189089105,531361846217471443,0,
%U A215615 28649272821614715410221,14214363393075742724609375,7526219790642312236217153392,5968603205606800870499639536231
%N A215615 From Wendt's determinant compute sqrt(abs(A048954(n))/(2^n - 1)).
%C A215615 E. Lehmer claimed, and J. S. Frame proved, that a(n) is an integer (Ribenboim 1999, p. 128).
%C A215615 The subsequence for even n is A129205.
%C A215615 See A048954 for additional comments, references, links, and cross-references.
%D A215615 P. Ribenboim, Fermat's Last Theorem for Amateurs, Springer-Verlag, NY, 1999, pp. 126, 136.
%F A215615 a(n) = ((-1)^(n-1)*A048954(n)/(2^n - 1))^(1/2).
%t A215615 w[n_] := Resultant[x^n - 1, (1 + x)^n - 1, x]; Table[ Sqrt[Abs[w[n]]/(2^n - 1)], {n, 25}]
%Y A215615 Cf. A048954, A129205, A215616.
%K A215615 nonn
%O A215615 1,3
%A A215615 _Jonathan Sondow_, Aug 17 2012