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Search: id:A137257
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| A137257 |
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A number n is included if there is at least one (nonzero) exponent in the prime-factorization of n that is not coprime to n. |
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1
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| 4, 12, 16, 18, 20, 24, 27, 28, 36, 44, 48, 50, 52, 54, 60, 64, 68, 72, 76, 80, 84, 90, 92, 98, 100, 108, 112, 116, 120, 124, 126, 132, 135, 140, 144, 148, 150, 156, 160, 162, 164, 168, 172, 176, 180, 188, 189, 192, 196, 198, 200, 204, 208, 212, 216, 220, 228, 234
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OFFSET
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1,1
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EXAMPLE
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48 = 2^4 * 3^1; so the exponents in the prime-factorization of 48 are 4 and 1. 48 is not coprime to 4; therefore 48 is included in this sequence.
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MATHEMATICA
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Select[Range[3000], GCD[ #, Product[FactorInteger[ # ][[i, 2]], {i, 1, Length[FactorInteger[ # ]]}]] > 1 &] - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Mar 16 2008
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CROSSREFS
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Adjacent sequences: A137254 A137255 A137256 this_sequence A137258 A137259 A137260
Sequence in context: A088510 A121728 A032823 this_sequence A119622 A067575 A082420
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KEYWORD
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nonn
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AUTHOR
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Leroy Quet (qq-quet(AT)mindspring.com), Mar 11 2008
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EXTENSIONS
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More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Mar 16 2008
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