A072417 a(n) = smallest positive m such that m! contains exactly n 0's, or 0 if no such m exists.

1, 5, 7, 0, 12, 18, 19, 20, 22, 25, 28, 34, 37, 42, 48, 41, 38, 53, 51, 50, 57, 63, 67, 66, 76, 68, 61, 80, 82, 79, 83, 0, 77, 104, 89, 73, 85, 94, 110, 109, 118, 108, 107, 0, 116, 105, 131, 114, 129, 137, 128, 115, 122, 124, 127, 0, 134, 135, 144, 159, 140

Offset

0,2

Links

Table of n, a(n) for n=0..60.

Example

a(1)=5: 5!=120, which has only 1 zero. Other numbers with only 1 zero are 6 and 9.
a(2)=7 since 7th factorial, i.e., 7!=5040 contains exactly two 0's.
a(3)=0 since no factorial contains just three zeros.

Crossrefs

Cf. A072419.

Sequence in context: A088394 A332328 A021950 * A133412 A111833 A011378

Adjacent sequences: A072414 A072415 A072416 * A072418 A072419 A072420

Keyword

base,nonn

Author

Shyam Sunder Gupta, Jul 31 2002

Extensions

Edited by N. J. A. Sloane, Sep 06 2008 at the suggestion of R. J. Mathar

Status

approved