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 A086723 #6 Feb 12 2013 08:31:18 %S A086723 8,5,3,2,7,6,0,8,8,3,1,4,0,8,0,8,0,4,4,1,0,2,8,6,6,3,2,8,9,3,9,4,8,5, %T A086723 9,4,3,6,8,9,7,7,1,2,8,6,1,3,7,2,3,7,1,1,9,0,0,4,7,7,3,4,5,4,2,4,8,2, %U A086723 2,3,8,9,6,3,0,6,2,7,6,9,5,6,2,9,2,0,6,9,0,0,1,2,2,2,7,2,7,5,7 %N A086723 Decimal expansion of 1/(g(1)+g(2)-g(4)-g(5)), where g(k) = sum(1/(6*m+k)^2,m=0..infinity). %D A086723 L. Fejes Toth, Lagerungen in der Ebene, auf der Kugel und im Raum, 2nd. ed., Springer-Verlag, Berlin, Heidelberg 1972; see p. 213. %e A086723 .85327608831408080... %t A086723 g[k_] := PolyGamma[1, k/6]/36; First[ RealDigits[1/(g[1] + g[2] - g[4] - g[5]), 10, 99]] (* _Jean-François Alcover_, Feb 12 2013 *) %Y A086723 Cf. A086722-A086731. %K A086723 nonn,cons %O A086723 0,1 %A A086723 _N. J. A. Sloane_, Jul 31 2003