A388780 Decimal expansion of 5 * (3+sqrt(5)) * exp(-Pi).

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

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} A225849(k) / exp(k*Pi).

Example

1.13135506801615593677387882714960546728090673630738861505707785642402752286....

Mathematica

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

Prog

(PARI) (1/32) * exp(-Pi) * (5-5^(1/2))^2 * (5^(1/2)+1)^4

Crossrefs

Cf. A225849.

Sequence in context: A082082 A388505 A016646 * A345943 A342342 A182600

Adjacent sequences: A388777 A388778 A388779 * A388781 A388782 A388783

Keyword

nonn,cons

Author

Simon Plouffe, Sep 18 2025

Status

approved