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A076251
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omega(n) = omega(n-1) + omega(n-2), where omega(n) is the number of distinct prime factors of n.
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0
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3, 6, 10, 18, 30, 33, 42, 60, 66, 84, 90, 102, 105, 110, 114, 126, 129, 130, 138, 150, 165, 168, 174, 180, 195, 198, 210, 228, 234, 252, 264, 270, 273, 285, 290, 294, 315, 318, 330, 345, 348, 354, 360, 385, 399, 402, 420, 434, 450, 462, 465, 468, 480, 504
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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EXAMPLE
| omega(18) = 2 = 1 + 1 = omega(17) + omega(16), so 18 belongs to the sequence.
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MATHEMATICA
| omega[n_] := Length[FactorInteger[n]]; Select[Range[3, 10^3], omega[ # ] == omega[ # - 1] + omega[ # - 2] &]
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CROSSREFS
| Cf. A001221.
Sequence in context: A092263 A170803 A182908 * A029864 A075111 A080014
Adjacent sequences: A076248 A076249 A076250 * A076252 A076253 A076254
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KEYWORD
| nonn
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AUTHOR
| Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Nov 04 2002
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