A388758 Decimal expansion of 2 * (7+3 * sqrt(5)) * exp(-Pi).

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

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} A210459(k) / exp(k*Pi).

Example

1.1847704085642981250309836438926145156...

Mathematica

First[RealDigits[2*(7 + 3*Sqrt[5])*Exp[-Pi], 10, 100]]

Prog

(PARI) (1/100) * exp(-Pi) * (5+5^(1/2))^4

Crossrefs

Cf. A210459.

Sequence in context: A387592 A388920 A388518 * A179260 A254246 A369103

Adjacent sequences: A388755 A388756 A388757 * A388759 A388760 A388761

Keyword

nonn,cons

Author

Simon Plouffe, Sep 18 2025

Status

approved