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 A244000 #6 Aug 09 2015 16:10:29 %S A244000 1,4,8,7,9,5,0,6,6,3,5,3,2,2,7,2,6,3,1,5,9,8,7,4,9,1,1,2,5,7,8,7,1,3, %T A244000 4,9,8,7,9,6,1,0,8,5,3,8,1,2,1,0,4,4,2,5,1,4,2,4,6,8,8,1,7,2,8,3,5,6, %U A244000 1,2,9,0,2,1,7,2,2,6,0,1,1,5,7,0,1,4,2,4,3,9,8,7,9,4,5,0,8,6,8,9,5 %N A244000 Decimal expansion of the Bateman-Grosswald constant zeta(2/3)/zeta(2), a constant (negated) arising in the asymptotic evaluation of the number of square-full numbers (also called "powerful" numbers). %D A244000 Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 2.6 Niven's constant, p. 113. %H A244000 Wikipedia, <a href="http://en.wikipedia.org/wiki/Powerful_number">Powerful number</a> %e A244000 -1.4879506635322726315987491125787134987961... %t A244000 RealDigits[ Zeta[2/3] / Zeta[2], 10, 101] // First %Y A244000 Cf. A001694, A033150, A059956 (analog for squarefree integers), A090699. %K A244000 nonn,cons %O A244000 1,2 %A A244000 _Jean-François Alcover_, Jun 17 2014