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Decimal expansion of Sum_{n>=0} 1/(1+n!).
1

%I #16 Aug 22 2024 11:41:56

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

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

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

%N Decimal expansion of Sum_{n>=0} 1/(1+n!).

%C Is there any known closed form for this sum?

%e 1.526068134473330824778047225162438405449754240466465650758365651679...

%t digits = 100; NSum[1/(1 + n!), {n, 0, Infinity}, NSumTerms -> digits, WorkingPrecision -> digits+5] // RealDigits[#, 10, digits]& // First

%Y Cf. A038507.

%K nonn,cons

%O 1,2

%A _Jean-François Alcover_, Mar 20 2013