id:A140330 - OEIS Search Results

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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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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; listen)

	OFFSET	`1,2`
	COMMENT	`This is to A061712 as A018252 is to A000040.` `Apart from the first term, identical to A089226. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 31 2008`
	FORMULA	`a(n) = MIN{k such that k is in A018252 and A000120(k) = n}.`
	EXAMPLE	`a(10) = 1023 because 1023 base 2 = 1111111111 which has 10 1's and 1023 = 3 * 11 * 31 is nonprime.`
	CROSSREFS	`Cf. A000040, A018252, A061712.` `Sequence in context: A107982 A063600 A116926 this_sequence A114634 A088017 A108977` `Adjacent sequences: A140327 A140328 A140329 this_sequence A140331 A140332 A140333`
	KEYWORD	`easy,nonn`
	AUTHOR	`Jonathan Vos Post (jvospost3(AT)gmail.com), May 26 2008`
	EXTENSIONS	`More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 31 2008`

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Last modified December 17 13:29 EST 2009. Contains 170826 sequences.

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