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Search: id:A076252
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| A076252 |
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omega(n) = omega(n-1) + omega(n-2) + omega(n-3), where omega(n) is the number of distinct prime factors of n. |
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+0
1
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| 2310, 3990, 4290, 6090, 6270, 10010, 11550, 12810, 13650, 17094, 17940, 18270, 19380, 21930, 22110, 22770, 23100, 24990, 25410, 27300, 28644, 30090, 32214, 32604, 34034, 34314, 35340, 35880, 37310, 38190, 38570, 38640, 39270, 39780
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OFFSET
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1,1
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EXAMPLE
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omega(2310) = 5 = 1 + 2 + 2 = omega(2309) + omega(2308) + omega(2307), so 2310 belongs to the sequence.
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MATHEMATICA
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omega[n_] := Length[FactorInteger[n]]; a = {}; Do[If[omega[n] == omega[n - 1] + omega[n - 2] + omega[n - 3], a = Append[a, n]], {n, 1, 10^5}]; a
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CROSSREFS
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Cf. A001221.
Sequence in context: A051270 A046387 A136154 this_sequence A046303 A046403 A087978
Adjacent sequences: A076249 A076250 A076251 this_sequence A076253 A076254 A076255
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KEYWORD
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nonn
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AUTHOR
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Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Nov 04 2002
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