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%I #19 Oct 16 2024 15:27:48
%S 1,2,6,5,6,2,5,0,5,9,6,0,4,6,4,4,7,7,5,3,9,0,6,2,5,0,0,0,0,0,0,0,0,0,
%T 0,0,0,7,5,2,3,1,6,3,8,4,5,2,6,2,6,4,0,0,5,0,9,9,9,9,1,3,8,3,8,2,2,2,
%U 3,7,2,3,3,8,0,3,9,4,5,9,5,6,3,3,4,1,3,6,0,1,3,7,6,5,6,0,1,0,9,2,0,1,8,1,8
%N Decimal expansion of Sum_{k>=0} 1/2^(k!).
%F Equals Sum_{k>=0} 1/A050923(k).
%F Equals A092874 plus 0.5. [_R. J. Mathar_, Sep 08 2008]
%e 1.2656250596046447753906250000000000007...
%t digits = 105; NSum[ 1/2^k!, {k, 0, 12} , WorkingPrecision -> digits] // RealDigits[#, 10, digits]& // First (* _Jean-François Alcover_, Mar 04 2013 *)
%t RealDigits[Total[1/2^Range[0,10]!],10,120][[1]] (* _Harvey P. Dale_, Oct 16 2024 *)
%o (PARI) suminf(k=0, 1/2^(k!)) \\ _Michel Marcus_, Feb 19 2021
%Y Cf. A050923, A092874.
%K cons,nonn
%O 1,2
%A _Benoit Cloitre_, Nov 02 2002