A388182 Decimal expansion of 2 * exp(-Pi / 2) * sqrt(2).

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

Offset

0,1

Links

Table of n, a(n) for n=0..86.

Simon Plouffe, Numbers in the base e^Pi, 2025.

Index entries for transcendental numbers.

Formula

Empirical: Equals Sum_{k>=0} A007249(k) / exp(k*Pi).

Example

0.58797223243124160156714048568507206885...

Mathematica

First[RealDigits[2*Sqrt[2]*Exp[-1/2*Pi], 10, 100]]

Prog

(PARI) 2 * exp(-Pi / 2) * sqrt(2)

Crossrefs

Cf. A007249.

Sequence in context: A357838 A143618 A177056 * A331676 A391358 A053787

Adjacent sequences: A388179 A388180 A388181 * A388183 A388184 A388185

Keyword

nonn,cons

Author

Simon Plouffe, Sep 15 2025

Status

approved