A388745 Decimal expansion of 2 * sqrt(2 * (2+sqrt(2))) * exp(-Pi/2).

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

Offset

1,3

Links

Table of n, a(n) for n=1..87.

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

Index entries for transcendental numbers.

Formula

Empirical: Equals Sum_{k>=0} A208589(k) / exp(k*Pi).

Example

1.0864310224563862568959917720805422480...

Mathematica

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

Prog

(PARI) 2 * exp(-Pi / 2) * sqrt(2) * (2+2^(1/2))^(1/2)

Crossrefs

Cf. A208589.

Sequence in context: A093019 A388399 A388664 * A175573 A296494 A388393

Adjacent sequences: A388742 A388743 A388744 * A388746 A388747 A388748

Keyword

nonn,cons

Author

Simon Plouffe, Sep 18 2025

Status

approved