A388380 Decimal expansion of 4 * exp(-Pi / 2) * sqrt(2).

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

Offset

1,3

Links

Paolo Xausa, Table of n, a(n) for n = 1..10000

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

Index entries for transcendental numbers.

Formula

Empirical: Equals Sum_{k>=0} A029841(k) / exp(k*Pi).

Example

1.1759444648624832031342809713701441377...

Mathematica

First[RealDigits[4*Exp[-Pi/2]*Sqrt[2], 10, 100]] (* Paolo Xausa, Sep 17 2025 *)

Prog

(PARI) 4 * exp(-Pi / 2) * sqrt(2)

Crossrefs

Cf. A029841.

Sequence in context: A388458 A195399 A065170 * A389109 A346589 A113816

Adjacent sequences: A388377 A388378 A388379 * A388381 A388382 A388383

Keyword

nonn,cons

Author

Simon Plouffe, Sep 15 2025

Status

approved