A092555 Decimal expansion of e^(-4).

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

Offset

0,3

Comments

This is one of Rényi's parking constants. - Alonso del Arte, Dec 28 2013

References

Steven R. Finch, Mathematical Constants, Cambridge University Press (2003): 280.

Links

Table of n, a(n) for n=0..104.

Formula

From Peter Bala, Nov 04 2025: (Start)

e^(-4) = Sum_{n >= 0} (-1)^n*binomial(2*n, n)/n! / Sum_{n >= 0} binomial(2*n, n)/n!.

e^(-4) = Sum_{n >= 0} (-1)^n*Catalan(n+1)/n! / Sum_{n >= 0} Catalan(n+1)/n!. (End)

Example

0.01831563888873418029371802127324124...

Mathematica

RealDigits[E^(-4), 10, 100][[1]] (* Alonso del Arte, Dec 28 2013 *)

Prog

(PARI) exp(-4) \\ Stefano Spezia, Feb 01 2026

Crossrefs

Cf. A019774, A001113, A068985, A092553 (e^(-2)), A092554 (e^(-3)).

Sequence in context: A388087 A388470 A388515 * A001061 A259073 A075525

Adjacent sequences: A092552 A092553 A092554 * A092556 A092557 A092558

Keyword

cons,nonn

Author

Mohammad K. Azarian, Apr 09 2004

Status

approved