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Search: id:A123904
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| A123904 |
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a(n) = n-th integer from among those positive integers with an exponent of n in their prime-factorizations. |
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+0
1
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| 2, 9, 27, 81, 243, 704, 1664, 3840, 8704, 19456, 43008, 94208, 204800, 442368, 950272, 2031616, 4325376, 9175040, 19398656, 40894464, 85983232, 180355072, 377487360, 788529152, 1644167168, 3422552064, 7113539584, 14763950080
(list; graph; listen)
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OFFSET
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1,1
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LINKS
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Leroy Quet, Home Page (listed in lieu of email address)
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EXAMPLE
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The positive integers with an exponent 6 in their prime-factorizations are 64 = 2^6, 192 = 2^6 *3^1, 320 = 2^6 *5^1, 448 = 2^6 *7^1, 576 = 2^6 *3^2, 704 = 2^6 *11^1, 729 = 3^6,...etc. The 6th of these is 704, so a(6) = 704.
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MATHEMATICA
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f[n_] := Min[3^n, 2^n*(2n - 1)]; Table[f[n], {n, 30}] (*Chandler*)
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CROSSREFS
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Sequence in context: A008910 A153977 A051746 this_sequence A128239 A019065 A115186
Adjacent sequences: A123901 A123902 A123903 this_sequence A123905 A123906 A123907
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KEYWORD
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nonn
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AUTHOR
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Leroy Quet Nov 19 2006
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EXTENSIONS
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Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 23 2006
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