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Search: id:A102246
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| A102246 |
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Number of distinct prime factors of prime p concatenated p-1 times. |
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+0
2
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| 1, 2, 3, 5, 7, 9, 10, 10, 10, 11, 19, 16, 14, 20, 22
(list; graph; listen)
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OFFSET
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1,2
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LINKS
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Dario Alejandro Alpern, Factorization using the Elliptic Curve Method.
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EXAMPLE
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If p=2, then the number of distinct prime factors of 2 is 1 since 2 is prime.
If p=3, then the number of distinct prime factors of 33 is 2.
If p=5, then the number of distinct prime factors of 5555 is 3.
If p=7, then the number of distinct prime factors of 777777 is 5.
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MATHEMATICA
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f[n_] := Length[ FactorInteger[ FromDigits[ Flatten[ Table[ IntegerDigits[ Prime[n]], {Prime[n] - 1}]] ]]]; Table[ f[n], {n, 10}]
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CROSSREFS
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Cf. A101081, A102245.
Sequence in context: A067090 A139790 A118784 this_sequence A089743 A080587 A063464
Adjacent sequences: A102243 A102244 A102245 this_sequence A102247 A102248 A102249
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KEYWORD
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nonn
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AUTHOR
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Parthasarathy Nambi (PachaNambi(AT)yahoo.com), Feb 18 2005
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EXTENSIONS
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More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Feb 21 2005
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