%I #28 Mar 19 2024 06:53:32
%S 1,9,8,9,2,8,0,2,3,4,2,9,8,9,0,1,0,2,3,4,2,0,8,5,8,6,8,7,4,2,1,5,1,6,
%T 3,8,1,4,9,4,4,6,0,7,7,0,7,4,2,5,0,2,7,0,9,0,7,8,1,5,3,9,9,2,9,2,3,0,
%U 2,5,9,4,9,3,6,3,2,3,5,4,0,2,1,1,2,6,6,8,8,8,3,4,9,0,3,5,8
%N Decimal expansion of zeta''(2), the second derivative of the Riemann zeta function at 2.
%H B. K. Choudhury, <a href="https://doi.org/10.1098/rspa.1995.0096">The Riemann zeta-function and its derivatives</a>, Proc. R. Soc. Lond A 445 (1995) 477-499, Table 2 and (19).
%H <a href="/wiki/Index_to_constants#Start_of_section_Z">Index entries for constants related to zeta</a>
%F zeta''(2) = Sum_{k>=1} (log(k)/k)^2.
%e Equals 1.9892802342989010234208586874215163814944...
%p evalf(Zeta(2,2),100) ;
%t RealDigits[ Zeta''[2], 10, 97] // First (* _Jean-François Alcover_, Feb 20 2013 *)
%o (PARI) zeta''(2) \\ _Michel Marcus_, Jan 07 2021
%Y Cf. A073002, A201995, A340442 (at 3), A340443 (at 4).
%K cons,nonn
%O 1,2
%A _R. J. Mathar_, Dec 07 2011