OFFSET
0,1
LINKS
M. L. Glasser, A note on Beukers's and related integrals, Amer. Math. Monthly 126(4) (2019), 361-363.
FORMULA
Equals Integral_{x=0..1} x/e^x dx.
Equals 1 - A135002.
Equals 1/A309419.
Equals -Integral_{x=0..1, y=0..1} x*y/(exp(x*y)*log(x*y)) dx dy. (Apply Theorem 1 or Theorem 2 of Glasser (2019) to the above integral.) - Petros Hadjicostas, Jun 30 2020
From Amiram Eldar, Aug 05 2020: (Start)
Equals Sum_{k>=0} (-1)^k/(k! * (k+2)).
Equals Sum_{k>=1} 1/((2*k)! * (k+1)).
EXAMPLE
0.2642411176571153568089524596770782651...
MATHEMATICA
RealDigits[1 - 2/E, 10, 100][[1]] (* Alonso del Arte, Apr 26 2020 *)
PROG
(PARI) 1 - 2/exp(1) \\ Michel Marcus, May 01 2020
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Daniel Hoyt, Apr 26 2020
STATUS
approved