A181583 Smallest prime p such that p! contains exactly n 0's (or 0, if no such p exists).
2, 5, 7, 0, 13, 23, 19, 29, 0, 0, 0, 47, 37, 43, 0, 41, 0, 53, 0, 59, 0, 0, 67, 0, 0, 71, 61, 0, 0, 79, 83, 0, 0, 0, 89, 73, 103, 0, 0, 109, 0, 0, 107, 0, 0, 0, 131, 0, 0, 137, 0, 0, 149, 0, 127, 0, 0, 139, 0, 0, 151, 0, 0, 0, 0, 0, 173, 0, 163, 0, 167, 199, 0, 0, 179, 0, 197, 0, 0, 0, 0, 0
Offset: 0
Examples
a(2) = 7 because 7! = 5040 is the first prime factorial followed by 11! = 39916800 to contain exactly 2 0's.
Extensions
More terms from Robert G. Wilson v, Nov 04 2010
Comments