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A154893
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Numbers whose number of proper divisors is not a prime number.
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0
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1, 2, 3, 5, 7, 11, 13, 16, 17, 19, 23, 29, 31, 36, 37, 41, 43, 47, 48, 53, 59, 61, 64, 67, 71, 73, 79, 80, 81, 83, 89, 97, 100, 101, 103, 107, 109, 112, 113, 120, 127, 131, 137, 139, 144, 149, 151, 157, 162, 163, 167, 168, 173, 176, 179, 181, 191, 193, 196, 197, 199
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| Complement of A063806.
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MATHEMATICA
| Select[Range[300], ! PrimeQ[DivisorSigma[0, # ] - 1] &] [From Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Jan 31 2009]
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CROSSREFS
| Cf. A032741, A063806.
Sequence in context: A062063 A167175 A026478 * A084111 A171474 A176548
Adjacent sequences: A154890 A154891 A154892 * A154894 A154895 A154896
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KEYWORD
| easy,nonn
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AUTHOR
| Omar E. Pol (info(AT)polprimos.com), Jan 25 2009
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EXTENSIONS
| More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Jan 31 2009
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