OFFSET
1,2
FORMULA
Equals Sum_{k>=0} 1/A050923(k).
Equals A092874 plus 0.5. [R. J. Mathar, Sep 08 2008]
EXAMPLE
1.2656250596046447753906250000000000007...
MATHEMATICA
digits = 105; NSum[ 1/2^k!, {k, 0, 12} , WorkingPrecision -> digits] // RealDigits[#, 10, digits]& // First (* Jean-François Alcover, Mar 04 2013 *)
RealDigits[Total[1/2^Range[0, 10]!], 10, 120][[1]] (* Harvey P. Dale, Oct 16 2024 *)
PROG
(PARI) suminf(k=0, 1/2^(k!)) \\ Michel Marcus, Feb 19 2021
CROSSREFS
KEYWORD
cons,nonn
AUTHOR
Benoit Cloitre, Nov 02 2002
STATUS
approved