A019763 Decimal expansion of 2*e/3.

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

Offset

1,2

References

Ovidiu Furdui, Limits, Series, and Fractional Part Integrals: Problems in Mathematical Analysis, New York: Springer, 2013. See Problem 3.114, p. 146 and 240-241.

Links

Ivan Panchenko, Table of n, a(n) for n = 1..1000

Université de La Rochelle, L2 - MG 2 - TD 5 - Exercice 4 (2020-2021).

Formula

Equals Sum_{m>=0} Sum_{k=0..m} (-1)^(m-k) / (k! * 2^(m-k)). - Bernard Schott, Oct 02 2021

Equals Sum_{n,m>=1} n*m/(n+m)! (Furdui, 2013). - Amiram Eldar, Mar 26 2022

Example

1.81218788563936349024...

Mathematica

RealDigits[2*E/3, 10, 100][[1]] (* Amiram Eldar, Mar 26 2022 *)

Prog

(PARI) 2*exp(1)/3 \\ Michel Marcus, Mar 26 2022

Crossrefs

Cf. A001113.

Sequence in context: A010154 A109011 A225767 * A307506 A179050 A176458

Adjacent sequences: A019760 A019761 A019762 * A019764 A019765 A019766

Keyword

nonn,cons

Author

N. J. A. Sloane

Status

approved