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Search: id:A072177
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| A072177 |
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a(n)-th factorial is the smallest factorial containing exactly n 3's, or 0 if no such number exists. |
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+0
9
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| 8, 15, 25, 36, 24, 49, 32, 54, 43, 69, 76, 89, 84, 113, 82, 105, 112, 92, 114, 106, 118, 107, 109, 151, 166, 143, 160, 149, 190, 152, 158, 172, 176, 0, 192, 181, 183, 177, 180, 202, 200, 193, 226, 238, 242, 223, 251, 227, 290, 261, 267, 292, 265, 300, 295, 285
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OFFSET
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1,1
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COMMENT
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It is conjectured that a(34)=0 since no factorial < 10000 contained just 34 threes.
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EXAMPLE
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a(2)=15 since 15-th factorial i.e. 15!=1307674368000 contains exactly two 3's.
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MATHEMATICA
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Do[k = 1; While[ Count[IntegerDigits[k! ], 3] != n, k++ ]; Print[k], {n, 1, 60}]
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CROSSREFS
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Cf. A072269, A072220, A072208, A072204, A072200, A072199, A072178, A072163 & A072124.
Sequence in context: A034114 A069826 A129076 this_sequence A031125 A132298 A123526
Adjacent sequences: A072174 A072175 A072176 this_sequence A072178 A072179 A072180
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KEYWORD
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base,nonn
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AUTHOR
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Shyam Sunder Gupta (guptass(AT)rediffmail.com), Jul 30 2002
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EXTENSIONS
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Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Jul 31 2002
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