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Search: id:A068186
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| A068186 |
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a(n) is the largest number whose product of decimal digits equals n^n. |
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+0
1
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| 22, 333, 22222222, 55555, 333333222222, 7777777, 222222222222222222222222, 333333333333333333, 55555555552222222222, 0, 3333333333332222222222222222222222222, 0, 7777777777777722222222222222
(list; graph; listen)
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OFFSET
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2,1
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COMMENT
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No digit=1 is permitted to avoid infinite number of solutions; a(n)=0 if A067734(n^n)=0.
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FORMULA
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a(n) is obtained as prime-factors of n^n concatenated in order of magnitude and with repetitions; a(n)=0 if n has p>7 prime factors.
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EXAMPLE
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n=10, 10^10=10000000000, a(5)=55555555552222222222
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CROSSREFS
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Cf. A000312, A001222, A002473, A067734, A068183-A068187, A068189-A068191.
Sequence in context: A053422 A000461 A048795 this_sequence A021284 A019623 A021794
Adjacent sequences: A068183 A068184 A068185 this_sequence A068187 A068188 A068189
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KEYWORD
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base,nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Feb 19 2002
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