OFFSET
0,3
LINKS
Eric Weisstein's World of Mathematics, Stirling's Series.
Eric Weisstein's World of Mathematics, Stirling's Approximation.
FORMULA
a(n) = floor(sqrt(2*Pi)*(n^n)*(n^(n/2))) - n!.
EXAMPLE
a(1) = Floor[(sqrt(2*pi) * (1^1) * (1^(1/2))) - 1! ] = Floor(1.50662827) = 1.
a(2) = Floor[(sqrt(2*pi) * (2^2) * (2^(2/2))) - 2! ] = Floor(18.0530262) = 18.
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, Apr 02 2007
EXTENSIONS
More terms from Alois P. Heinz, Jan 24 2024
STATUS
approved