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A072417
a(n) = smallest positive m such that m! contains exactly n 0's, or 0 if no such m exists.
1
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
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
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