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 A231132 #13 Feb 16 2025 08:33:20
%S A231132 3,2,0,3,4,1,1,4,2,5,1,2,7,9,3,8,3,6,2,7,2,5,6,1,0,9,3,2,1,1,7,7,8,7,
%T A231132 1,8,7,5,3,2,1,1,4,7,9,8,7,6,2,0,3,2,3,8,5,2,0,8,9,6,9,3,1,3,3,5,7,1,
%U A231132 3,3,4,8,6,8,0,4,0,7,3,2,2,0,1,6,9,3,0,4,6,3,1,9,2,1,2,0,8,8,0,3
%N A231132 Decimal expansion of sum_(n=2..infinity) (-1)^n*zeta(n)/n^2.
%C A231132 Let f(k) = sum_(n=2..infinity) (-1)^n*zeta(n)/n^k, then Euler gamma is f(1) and this constant is f(2).
%H A231132 Eric Weisstein's MathWorld, <a href="https://mathworld.wolfram.com/Euler-MascheroniConstant.html">Euler-Mascheroni Constant</a>
%e A231132 0.32034114251279383627256109321177871875321147987620323852089693133571334868...
%t A231132 RealDigits[ EulerGamma + Integrate[ LogGamma[x+1]/x, {x, 0, 1}] // N[#, 100]&, 10, 100] // First
%o A231132 (PARI) sumalt(k=2,(-1)^k*zeta(k)/k^2) \\ _Vaclav Kotesovec_, Sep 23 2023
%Y A231132 Cf. A001620, A352619, A355921, A365959.
%K A231132 nonn,cons
%O A231132 0,1
%A A231132 _Jean-François Alcover_, Nov 04 2013