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A198377
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Smallest nonprime number with multiplicative persistence n.
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0
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0, 10, 25, 39, 77, 679, 6788, 68889, 2677889, 26888999, 3778889989, 277777788888899
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OFFSET
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0,2
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COMMENTS
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Probably finite sequence. The multiplicative 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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EXAMPLE
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For n=4, a(4) = 39 because 39 is the smallest nonprime number with multiplicative persistence 3: 39 -> 27 -> 14 -> 4.
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CROSSREFS
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Cf. A046500 (smallest prime with multiplicative persistence n).
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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