A394924 Decimal expansion of e^(-3/2).

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

Offset

0,1

Comments

This constant gives the asymptotic probability that a randomly selected permutation of length n is a 2-derangement (see Bona at p. 410): A038205(n) ~ exp(-3/2)*n!.

References

Miklos Bona, Introduction to Enumerative and Analytic Combinatorics, CRC Press, 2025, p. 410.

Links

Table of n, a(n) for n=0..99.

Example

0.22313016014842982893328047076401252134217162936...

Mathematica

RealDigits[Exp[-3/2], 10, 100][[1]]

Crossrefs

Cf. A001113, A038205.

Sequence in context: A088598 A200751 A077083 * A274528 A166248 A180257

Adjacent sequences: A394921 A394922 A394923 * A394925 A394926 A394927

Keyword

nonn,cons,easy

Author

Stefano Spezia, Apr 07 2026

Status

approved