A086056 Decimal expansion of Pi/(2e).

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

Offset

0,1

Links

Table of n, a(n) for n=0..101.

V. S. Adamchik, The Multiple Gamma Function and Its Application to Computation of Series, Ramanujan J. vol. 9, no 3. (2005) 271-288.

Christophe Chesneau, An original approximation involving Pi, the Euler-Mascheroni constant and the Catalan constant, hal-04692308v1, [math], 2024.

Z. A. Melzak, Infinite products for πe and π/e, Amer. Math. Monthly 68 (1961) 39-41.

Eric Weisstein's World of Mathematics, Masser-Gramain Constant

Eric Weisstein's World of Mathematics, Euler-Mascheroni Constant Approximations

Eric Weisstein's World of Mathematics, InfiniteProduct

Formula

Equals Integral_{x>=0} cos(x)/(x^2+1) dx = Integral_{x>=0} x*sin(x)/(x^2+1) dx. - Jean-François Alcover, Mar 28 2013

Equals Product_{k>=1} (1 + 2/k)^((-1)^(k+1) * k). - Amiram Eldar, Jul 16 2020

Example

0.577863674895...

Maple

Digits:=100: evalf(Pi/(2*exp(1))); # Wesley Ivan Hurt, Jan 07 2017

Mathematica

First@ RealDigits@ N[Pi/(2 E), 120] (* Michael De Vlieger, Jan 07 2017 *)

Prog

(PARI) Pi/(2*exp(1)) \\ Michel Marcus, Jan 07 2017

Crossrefs

Cf. A216184: Integral_{x>=0} sin(x)/(x^2+1).

Sequence in context: A065773 A114916 A001989 * A154475 A375336 A264527

Adjacent sequences: A086053 A086054 A086055 * A086057 A086058 A086059

Keyword

nonn,cons,easy,changed

Author

Eric W. Weisstein, Jul 07 2003

Status

approved