OFFSET
1,2
COMMENTS
Average length of the 2nd increasing run in a random permutation of n integers as n->Infinity.
LINKS
Eric Weisstein's World of Mathematics, Permutation
FORMULA
Equals (Sum_{n>0}(Sum_{k>0} 1/(n!*k!)))-1. - Fredrik Johansson, Apr 21 2006
EXAMPLE
-2*e + e^2 = 1.95249244...
MATHEMATICA
RealDigits[E^2-2*E, 10, 120][[1]] (* Harvey P. Dale, Nov 04 2019 *)
CROSSREFS
KEYWORD
AUTHOR
Eric W. Weisstein, Dec 19 2003
STATUS
approved