auxiliary {randtoolbox} | R Documentation |
Stirling numbers of the second kind
stirling(n)
n |
a positive integer. |
stirling
computes stirling numbers of second kind i.e.
Stirl_n^k = k * Stirl_{n-1}^k + Stirl_{n-1}^{k-1}
with Stirl_n^1 = Stirl_n^n = 1. e.g. n = 0, returns 1 n = 1, returns c(0,1) n = 2, returns c(0,1,1) n = 3, returns c(0,1,3,1) n = 4, returns c(0,1,7,6,1)... Go to wikipedia for more details.
a vector with stirling numbers.
Christophe Dutang.
choose
for combination numbers.
# should be 1 stirling(0) # should be 0,1,7,6,1 stirling(4)