OFFSET
2,2
COMMENTS
Expected number of picks from a uniform [0,1] needed to first exceed a sum of 6.
REFERENCES
J. V. Uspensky, Introduction to Mathematical Probability, New York: McGraw-Hill, 1937.
LINKS
Daniel Mondot, Table of n, a(n) for n = 2..10001
Eric Weisstein's World of Mathematics, Uniform Sum Distribution.
FORMULA
Equals Sum_{k=0..n} (-1)^k * (n-k+1)^k * exp(n-k+1) / k! for n = 5 (Uspensky, 1937, p. 278).
EXAMPLE
12.6666671413781214013719357626849111...
MATHEMATICA
RealDigits[E^6 - 5*E^5 + 8*E^4 - 9*E^3/2 + 2*E^2/3 - E/120, 10, 120][[1]]
PROG
(PARI) exp(6)-5*exp(5)+8*exp(4)-9*exp(3)/2+2*exp(2)/3-exp(1)/120
CROSSREFS
KEYWORD
AUTHOR
Daniel Mondot, Feb 27 2025
STATUS
approved
