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Search: id:A046500
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| A046500 |
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Smallest prime with multiplicative persistence n. |
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+0
11
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| 2, 11, 29, 47, 277, 769, 8867, 186889, 2678789, 26899889, 3778888999, 277777788888989
(list; graph; listen)
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OFFSET
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0,1
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COMMENT
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The persistence of a number is the number of times you need to multiply the digits together before reaching a single digit.
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LINKS
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C. Rivera, Puzzle page
N. J. A. Sloane, The persistence of a number, J. Recreational Math., 6 (1973), 97-98.
Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.
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EXAMPLE
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47 -> 28 -> 16 -> 6 has persistence 3.
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CROSSREFS
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Cf. A003001, A014120.
Sequence in context: A136317 A090389 A061238 this_sequence A062123 A117560 A024178
Adjacent sequences: A046497 A046498 A046499 this_sequence A046501 A046502 A046503
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KEYWORD
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nonn,hard,base,nice
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AUTHOR
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Patrick De Geest (pdg(AT)worldofnumbers.com), Sep 15 1998.
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EXTENSIONS
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Value for n=10 and n=11 found by Jud McCranie.
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