A388447 Decimal expansion of 2 * exp(-Pi / 2) * (1+3^(1/2)).

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

Offset

1,3

Links

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

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

Formula

Empirical: Equals Sum_{k>=0} A058571(k) / exp(k*Pi).

Example

1.1358751288923503161692477472100893329...

Mathematica

First[RealDigits[2*(1 + Sqrt[3])*Exp[-1/2*Pi], 10, 100]]

Prog

(PARI) 2 * exp(-Pi / 2) * (1+3^(1/2))

Crossrefs

Cf. A058571.

Sequence in context: A368741 A021740 A172370 * A304026 A110641 A379042

Adjacent sequences: A388444 A388445 A388446 * A388448 A388449 A388450

Keyword

nonn,cons

Author

Simon Plouffe, Sep 15 2025

Status

approved