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A140330
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Smallest nonprime with Hamming weight n (i.e. with exactly n 1's when written in binary).
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0
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1, 6, 14, 15, 55, 63, 247, 255, 511, 1023, 2047, 4095, 12287, 16383, 32767, 65535, 196607, 262143, 983039, 1048575, 2097151, 4194303, 8388607, 16777215, 33554431, 67108863, 134217727, 268435455, 536870911, 1073741823, 3221225471
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| Apart from the first term, identical to A089226. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 31 2008
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FORMULA
| a(n) = MIN{k such that k is in A018252 and A000120(k) = n}.
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EXAMPLE
| a(10) = 1023 because 1023 base 2 = 1111111111 which has 10 1's and 1023 = 3 * 11 * 31 is nonprime.
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CROSSREFS
| Cf. A061712.
Sequence in context: A107982 A063600 A116926 * A114634 A088017 A206524
Adjacent sequences: A140327 A140328 A140329 * A140331 A140332 A140333
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KEYWORD
| easy,nonn
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AUTHOR
| Jonathan Vos Post (jvospost3(AT)gmail.com), May 26 2008
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EXTENSIONS
| More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 31 2008
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