A121061 - OEIS

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A121061

Numbers n such that n-th partition number A000041(n) is a 3-almost prime (A014612).

9, 10, 16, 18, 20, 22, 25, 29, 31, 34, 37, 42, 45, 48, 50, 56, 57, 60, 63, 69, 71, 72, 73, 83, 85, 91, 101, 102, 112, 113, 114, 119, 139, 144, 148, 151, 155, 156, 172, 175, 183, 185, 190, 192, 195, 202, 208, 217, 238, 242, 244, 245, 247, 256, 257, 272, 275, 291, 293 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	COMMENTS	`3-almost prime analogue of: A046063 Numbers n such that n-th partition number A000041(n) is prime; A065729 n-th partition number (A000041[n]) is a semiprime. see also: A065728 Partition numbers (A000041) that are semiprimes (A001358).`
	FORMULA	`A000041[a(n)] in A014612.`
	EXAMPLE	`a(1) = 9 because P(9) = 30 = 2 * 3 * 5.` `a(2) = 10 because P(10) = 42 = 2 * 3 * 7.` `a(3) = 16 because P(16) = 231 = 3 * 7 * 11.`
	CROSSREFS	`Cf. A000041, A046063, A065728, A065729.` `Sequence in context: A003135 A105742 A105834 * A106690 A173015 A045568` `Adjacent sequences: A121058 A121059 A121060 * A121062 A121063 A121064`
	KEYWORD	`easy,nonn`
	AUTHOR	`Jonathan Vos Post (jvospost3(AT)gmail.com), Aug 09 2006`
	EXTENSIONS	`112 and 113 inserted by R. J. Mathar, Dec 22 2010`

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Last modified February 17 16:49 EST 2012. Contains 206058 sequences.