login
Decimal expansion of constant C such that Sum_{k>=1} 1/C^p(k) = 1 where p(k) is the k-th prime.
2

%I #20 Apr 20 2016 08:37:20

%S 1,4,7,6,2,2,8,7,8,3,6,2,0,8,9,6,9,6,5,7,9,2,9,4,3,9,9,4,8,4,8,2,3,3,

%T 2,9,4,7,9,7,1,2,2,7,6,0,8,5,0,5,9,3,2,7,0,7,5,5,1,9,0,0,2,0,1,7,6,8,

%U 3,2,2,8,0,7,4,1,8,2,4,6,5,6,6,4,8,4,1,1,3,1,5,6,1,9,2,5,9,0,2,0,8,6,7,5,1

%N Decimal expansion of constant C such that Sum_{k>=1} 1/C^p(k) = 1 where p(k) is the k-th prime.

%D Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.5 Kalmar's Composition Constant, p. 293.

%F Equals 1/A084256.

%e 1.47622878362089696579294399484823329479712276085059327075519...

%t RealDigits[x/.FindRoot[Sum[1/x^Prime[k], {k,1,120}] == 1, {x, 1.476}, WorkingPrecision -> 120]][[1, 1 ;; 105]] (* _Jean-François Alcover_, Mar 22 2011 *)

%Y Cf. A078465, A084256.

%K cons,nonn

%O 1,2

%A _Benoit Cloitre_, Jan 12 2003