A091131 - OEIS (original) (raw)

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

COMMENTS

Average length of the first increasing run in a random permutation of n integers as n->Infinity.

Engel expansion of number e - 1 is sequence of natural numbers (A000027). - Jaroslav Krizek, Jan 23 2014

LINKS

Eric Weisstein's World of Mathematics, Permutation

FORMULA

Equals Sum_{k>=1} H(k)*(k-1)/k!, where H(k) = A001008(k)/A002805(k) is the k-th harmonic number. - Amiram Eldar, Aug 19 2020

MATHEMATICA

RealDigits[N[E - 1, 105]][[1]]