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 A324835 #7 Mar 31 2025 14:33:18
%S A324835 0,1,2,5,9,3,0,2,8,3,9,8,6,4,2,0,1,3,6,5,2,9,9,1,1,0,2,2,6,2,2,9,2,1,
%T A324835 7,6,9,4,7,3,4,3,2,0,8,9,8,5,4,2,2,1,8,6,1,4,7,2,5,7,8,9,3,6,6,9,5,4,
%U A324835 7,5,7,7,9,0,8,4,7,0,9,9,1,8,3,2,8,4,7,7,0,8,9,7,8,5,9,1,1,0,1,3,9,8
%N A324835 Decimal expansion of eta_4, a constant related to the asymptotic density of certain sets of residues.
%H A324835 Carl Pomerance, Andrzej Schinzel, <a href="http://mjcnt.phystech.edu/en/article.php?id=4">Multiplicative Properties of Sets of Residues</a>, Moscow Journal of Combinatorics and Number Theory. 2011. Vol. 1. Iss. 1. pp. 52-66. See p. 62.
%F A324835 Sum_{p prime} 1/(p^2-1)^4.
%F A324835 Sum_{n>0} (n(n+1)(n+2)/6) P(2n+6) where P is the prime zeta P function.
%e A324835 0.0125930283986420136529911022622921769473432089854221861472578936695...
%t A324835 digits = 101; m0 = 2 digits; Clear[rd]; rd[m_] := rd[m] = RealDigits[eta4 = Sum[n(n+1)(n+2)/6 PrimeZetaP[2n+6], {n, 1, m}], 10, digits][[1]]; rd[m0]; rd[m = 2 m0]; While[rd[m] != rd[m-m0], Print[m]; m = m+m0]; Print[N[eta4, digits]]; rd[m]
%Y A324835 Cf. A154945 (eta_1), A324833 (eta_2), A324834 (eta_3), A324836 (eta_5).
%K A324835 nonn,cons
%O A324835 0,3
%A A324835 _Jean-François Alcover_, Mar 17 2019