A388684 Decimal expansion of (2 * (3+sqrt(3))) / 9.

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

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 algebraic numbers, degree 2.

Formula

Empirical: Equals Sum_{k>=0} A164617(k) / exp(k*Pi).

Example

1.05156684612641717633943252033463830376506783418008458401240155098931844820....

Mathematica

First[RealDigits[(2*(3 + Sqrt[3]))/9, 10, 100]]

Prog

(PARI) (1/6) * gamma(2/3)^2 * gamma(7/12) * (1+3^(1/2))^2 / Pi / gamma(11/12)
(PARI) (2 * (3+sqrt(3))) / 9 \\ Charles R Greathouse IV, May 19 2026

Crossrefs

Cf. A164617.

Sequence in context: A054244 A093562 A081774 * A103193 A011093 A062176

Adjacent sequences: A388681 A388682 A388683 * A388685 A388686 A388687

Keyword

nonn,cons

Author

Simon Plouffe, Sep 18 2025

Status

approved