%I #30 Nov 23 2021 10:36:12
%S 6,9,2,6,0,5,8,1,4,6,7,4,2,4,9,3,2,7,5,1,3,8,6,3,9,4,8,8,6,1,9,5,6,3,
%T 0,5,4,3,5,9,2,1,7,3,3,4,9,5,1,7,2,4,9,4,3,7,5,3,9,9,0,7,6,3,3,7,2,3,
%U 8,5,5,9,9,2,1,2,9,2,6,6,8,2,1,7,1
%N Decimal expansion of Sum_{k>=2} 1/(k*log(k))^2.
%C Theorem: Bertrand series Sum_{n>=2} 1/(n^q*log(n)^r) is convergent if q > 1.
%C Application for q = 2 with A201994 (r=-2), A073002 (r=-1), A013661 (r=0), A168218 (r=1), this sequence (r=2).
%H Wikipédia, <a href="https://fr.wikipedia.org/wiki/Série_de_Bertrand">Série de Bertrand</a> (in French).
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Joseph_Bertrand">Joseph Bertrand</a>.
%F Equals Sum_{k>=2} 1/(k*log(k))^2.
%F Equals Integral_{x>=2, y>=2} (zeta(x + y - 2) - 1) dx dy. - _Amiram Eldar_, Nov 21 2021
%e 0.6926058...
%o (PARI) sumpos(k=2, 1/(k*log(k))^2) \\ _Michel Marcus_, Nov 21 2021
%Y Cf. A013661, A073002, A168218, A201994.
%K nonn,cons
%O 0,1
%A _Bernard Schott_, Nov 20 2021