%I #11 Mar 14 2017 20:56:10
%S 1,5,3,7,9,3,9,8,6,0,6,7,5,1,2,6,1,7,4,9,5,7,9,0,8,6,0,7,3,1,2,1,2,2,
%T 1,3,6,7,4,9,8,6,3,1,0,8,4,2,5,2,1,0,7,6,2,2,1,4,5,7,2,3,5,7,9,4,3,1,
%U 1,9,6,6,9,3,3,8,3,5,1,4,1,7,0,5,4,4,7,9,3
%N Constant appearing in the Nicolas-Robin bound for the divisor function.
%C The number of divisors of n is at most 2^(k * log n/log log n) where k is this constant. Equality is attained precisely at n = 6983776800.
%H Indranil Ghosh, <a href="/A280235/b280235.txt">Table of n, a(n) for n = 1..150</a>
%H J. L. Nicolas and G. Robin, <a href="http://dx.doi.org/10.4153/CMB-1983-078-5">Majorations explicites pour le nombre de diviseurs de N</a>, Canadian Mathematical Bulletin 26 (1983), pp. 485-492.
%e 1.53793986067512617495790860731212213674986310842521076221457235794311...
%t L = Log[6983776800]; RealDigits[2 * Log[48] * Log[L] / L / Log[2], 10, 89][[1]] (* _Indranil Ghosh_, Mar 12 2017 *)
%o (PARI) L=log(6983776800); 2*log(48)*log(L)/L/log(2)
%Y Cf. A217660.
%K cons,nonn
%O 1,2
%A _Charles R Greathouse IV_, Feb 25 2017