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 A344125 #33 Aug 25 2021 12:53:57
%S A344125 1,0,6,8,5,9,2,1,0,5,6,5,4,9,9,0,1,3,5,2,0,2,9,4,8,0,2,0,7,4,3,2,4,3,
%T A344125 6,1,3,6,1,3,3,3,5,9,0,8,1,0,1,7
%N A344125 Decimal expansion of Sum_{i > 0} 1/A001481(i)^4.
%C A344125 This constant can be considered as an analog of zeta(4) (= Pi^4/90 = A013662), where Euler's zeta(4) is over all positive integers, with prime elements in A000040, while this constant is over all positive integers that can be written as the sum of two squares (A001481) with prime elements given in A055025.
%H A344125 R. J. Mathar, <a href="http://arxiv.org/abs/1008.2547">Table of Dirichlet L-series and Prime Zeta Modulo Functions for Small Moduli</a>, arXiv:1008.2547 [math.NT], 2010-2015.
%F A344125 Equals Sum_{i > 0} 1/A001481(i)^4.
%F A344125 Equals Product_{i > 0} 1/(1-A055025(i)^-4).
%F A344125 Equals 1/(1-prime(1)^(-4)) * Product_{i>1 and prime(i) == 1 (mod 4)} 1/(1-prime(i)^(-4)) * Product_{i>1 and prime(i) == 3 (mod 4)} 1/(1-prime(i)^(-8)), where prime(n) = A000040(n).
%F A344125 Equals zeta_{2,0} (4) * zeta_{4,1} (4) * zeta_{4,3} (8), where zeta_{2,0} (s) = 2^s/(2^s - 1).
%e A344125 1.0685921056549901352029480207432436136133359081017...
%Y A344125 Cf. A000040, A001481, A055025.
%Y A344125 Cf. A344123, A344124.
%K A344125 nonn,cons,more
%O A344125 1,3
%A A344125 _A.H.M. Smeets_, May 09 2021