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A112887
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Semiprime(n) - composite(n).
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0
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0, 0, 1, 1, 4, 3, 7, 7, 9, 8, 13, 13, 13, 14, 14, 20, 22, 23, 25, 25, 25, 28, 30, 33, 36, 38, 42, 43, 42, 42, 45, 45, 45, 45, 55, 59, 61, 63, 63, 64, 64, 63, 67, 70, 70, 76, 76, 75, 76, 76, 83, 84, 84, 85, 89, 91, 97, 97, 101, 101, 102, 108, 114, 114, 113, 114, 114, 116, 119
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,5
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COMMENTS
| The first occurrence where the sequence has k similar terms: 4, 0, 13, 45, 857, 523807, 119, ...
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MATHEMATICA
| Select[ Range@225, Plus @@ Last /@ FactorInteger@# == 2 &] - Select[ Range[2, 102], !PrimeQ[ # ] &]
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CROSSREFS
| Cf. A002808, A001358.
Sequence in context: A131413 A205392 A168200 * A010654 A048227 A176083
Adjacent sequences: A112884 A112885 A112886 * A112888 A112889 A112890
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KEYWORD
| nonn
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AUTHOR
| Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 31 2005
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EXTENSIONS
| Definition corrected by Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), May 17 2010
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