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 A258102 #17 Dec 27 2022 16:53:44
%S A258102 1,0,6,2,5,5,0,8,0,5,4,9,6,2,5,5,9,3,7,8,6,9,4,4,5,9,3,8,7,9,3,3,7,5,
%T A258102 8,6,3,2,8,5,4,8,4,1,5,7,3,3,8,6,2,6,3,2,0,1,0,7,8,1,0,8,5,9,1,6,5,7,
%U A258102 6,1,1,6,4,9,0,1,4,4,8,1,7,6,8,6,3,2,1,4,9,6,3,9,6,1,6,3,1,3,1,8,8,3,7,6,4
%N A258102 Decimal expansion of Sum_{k >= 1} k^(-k^2).
%H A258102 G. C. Greubel, <a href="/A258102/b258102.txt">Table of n, a(n) for n = 1..1000</a>
%H A258102 MathOverflow, <a href="http://mathoverflow.net/questions/206034">What is a "generalized zeta function"?</a>
%e A258102 1.06255080549625593786944593879337586328548415733862632010781...
%p A258102 evalf(Sum(k^(-k^2), k=1..infinity), 120); # _Vaclav Kotesovec_, May 21 2015
%t A258102 NSum[k^(-k^2), {k, 1, Infinity}, WorkingPrecision -> 105] // RealDigits // First
%o A258102 (PARI) default(realprecision,120); sumpos(k=1, k^(-k^2)) \\ _Vaclav Kotesovec_, May 21 2015
%Y A258102 Cf. A073009.
%K A258102 nonn,cons,easy
%O A258102 1,3
%A A258102 _Jean-François Alcover_, May 20 2015