A245422 Decimal expansion of the coefficient c appearing in the expression of the asymptotic expected shortest cycle in a random n-cyclation as c*sqrt(n).

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

Offset

1,2

Links

Table of n, a(n) for n=1..102.

Steven R. Finch, Errata and Addenda to Mathematical Constants, p. 35.

Nicholas Pippenger, Random cyclations, arXiv:math /0408031 [math.CO]

Formula

(sqrt(Pi)/2)*integral_{0..infinity} exp(-x - Ei(-x)/2), where Ei is the exponential integral function.

Example

1.457270879273653853694454068120047059660530020235224659213297...

Mathematica

digits = 102; (Sqrt[Pi]/2)*NIntegrate[Exp[-x - ExpIntegralEi[-x]/2], {x, 0, Infinity}, WorkingPrecision -> digits+10] // RealDigits[#, 10, digits]& // First

Crossrefs

Cf. A143297 (analog in the case of the expected *longest* cycle in a random cyclation).

Sequence in context: A322711 A057055 A177883 * A272005 A274984 A114343

Adjacent sequences: A245419 A245420 A245421 * A245423 A245424 A245425

Keyword

nonn,cons,easy

Author

Jean-François Alcover, Sep 08 2014

Status

approved