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A074213
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Sum of the prime factors of n equals half the sum of the prime factors of n + 1.
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0
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90, 208, 867, 1161, 1674, 2139, 2295, 2821, 3683, 9675, 10374, 11357, 14823, 17685, 20436, 23750, 23895, 28035, 39039, 39962, 43687, 43813, 47564, 63624, 75615, 79281, 97382
(list; graph; refs; listen; history; internal format)
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OFFSET
| 2,1
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EXAMPLE
| The sum of the prime factors of 90 = 2 * 3^2 * 5 is 2 + 3 + 5 = 10; the sum of the prime factors of 91 = 7 * 13 = 20. Hence 90 belongs to the sequence.
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MATHEMATICA
| p[n_] := Apply[Plus, Transpose[FactorInteger[n]][[1]]]; Select[Range[2, 10^5], 2*p[ # ] == p[ # + 1] &]
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CROSSREFS
| Sequence in context: A179697 A044422 A044803 * A027621 A157888 A201103
Adjacent sequences: A074210 A074211 A074212 * A074214 A074215 A074216
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KEYWORD
| nonn
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AUTHOR
| Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Oct 18 2002
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