A388430 Decimal expansion of sqrt(-2/5+1 / sqrt(5)) * exp(Pi / 2).

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

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} A036026(k) / exp(k*Pi).

Example

1.0452537020039188234662614604225304216...

Mathematica

First[RealDigits[Sqrt[-2/5 + 1/Sqrt[5]]*Exp[Pi/2], 10, 100]]

Prog

(PARI) (1/25600) * exp(Pi / 2) * 2^(2/5) * 5^(3/4) * gamma(4/5)^6 * (5-5^(1/2))^3 * (5^(1/2)-1)^3 * (5^(1/2)+1)^3 / gamma(9/10)^3 / gamma(7/10)^3

Crossrefs

Cf. A036026.

Sequence in context: A388690 A292820 A388486 * A388177 A178040 A090201

Adjacent sequences: A388427 A388428 A388429 * A388431 A388432 A388433

Keyword

nonn,cons

Author

Simon Plouffe, Sep 15 2025

Status

approved