A100127 - OEIS

A100127

Decimal expansion of Sum_{n>0} prime(n)/n!.

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

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OFFSET

1,1

COMMENTS

This constant is irrational (Erdős, 1958). - Amiram Eldar, Apr 13 2020

LINKS

Table of n, a(n) for n=1..105.

Paul Erdős, Sur certaines séries à valeur irrationnelle (in French), Enseignement Math. (2) 4 (1958), pp. 93-100.

EXAMPLE

4.73863870268621999271779470348124955360182384664210664248096193484375408779697167489...

MATHEMATICA

RealDigits[ Sum[ Prime[n]/n!, {n, 75}], 10, 105][[1]] (* Robert G. Wilson v, Jan 18 2015 *)