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 A282821 #7 Mar 03 2017 14:45:57
%S A282821 2,4,8,1,7,1,4,1,1,4,4,7,5,3,4,9,7,0,3,9,2,7,5,7,5,3,1,4,7,2,5,7,6,7,
%T A282821 8,5,9,3,6,2,8,1,6,4,1,0,7,0,8,3,3,4,7,1,5,7,0,3,8,8,8,3,7,5,4,7,0,5,
%U A282821 7,3,2,8,2,6,0,0,4,8,7,6,8,5,1,9,0,8,4,7,9,2,1
%N A282821 Decimal expansion of Sum_{k >= 0} (4/(4*k+1) - 3/(3*k+1) + 2/(2*k+1) - 1/(k+1)).
%C A282821 It is known that Sum_{k >= 0} Sum_{i = 1..h} (-1)^i*i/(i*k + 1) diverges for h = 3. This is the case h = 4, A016627 corresponds to the case h = 2.
%F A282821 Equals (3 - sqrt(3))*Pi/6 + log(32) - log(27)/2.
%e A282821 2.48171411447534970392757531472576785936281641070833471570388837547057328...
%t A282821 RealDigits[(3 - Sqrt[3]) Pi/6 + Log[32] - Log[27]/2, 10, 100][[1]]
%Y A282821 Cf. A016627.
%K A282821 nonn,cons
%O A282821 1,1
%A A282821 _Bruno Berselli_, Mar 03 2017