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Search: id:A067173
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| A067173 |
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Numbers n such that the sum of the prime factors of n equals the product of the digits of n. |
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+0
2
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| 2, 3, 5, 7, 126, 154, 315, 329, 342, 418, 442, 1134, 1826, 2354, 3383, 4343, 5282, 5561, 6623, 7515, 7922, 9331, 9911, 12773, 13344, 14161, 15194, 17267, 18292, 21479, 22831, 26216, 26522, 29812, 32129, 33128, 33912, 57721, 81191, 81524
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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The prime factors of 315 are 3,5,7, which sum to 15, the product of the digits of 315, so 315 is a term of the sequence.
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MATHEMATICA
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f[n_] := Module[{a, l, t, r}, a = FactorInteger[n]; l = Length[a]; t = Table[a[[i]][[1]], {i, 1, l}]; r = Sum[t[[i]], {i, 1, l}]]; g[n_] := Module[{b, m, s}, b = IntegerDigits[n]; m = Length[b]; s = Product[b[[i]], {i, 1, m}]]; Select[Range[10^5], f[ # ] == g[ # ] &]
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CROSSREFS
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Cf. A006753.
Sequence in context: A076609 A117059 A117058 this_sequence A090718 A117703 A039944
Adjacent sequences: A067170 A067171 A067172 this_sequence A067174 A067175 A067176
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KEYWORD
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base,nonn
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AUTHOR
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Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Feb 18 2002
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