id:A080405 - OEIS Search Results

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Number of distinct primes dividing n-th Catalan number.

+0
4

0, 0, 1, 1, 2, 3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 7, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 10, 11, 11, 11, 11, 12, 13, 13, 13, 13, 13, 13, 14, 14, 15, 15, 15, 16, 16, 16, 17, 17, 17, 17, 17, 17, 19, 18, 18, 18, 18, 19, 19, 20, 20, 20, 20, 21, 22, 22, 23, 22, 22, 22, 23, 23, 23, 24, 24, 25, 25 (list; graph; listen)

	OFFSET	`0,5`
	FORMULA	`a(n)=A001221[A000108(n)]`
	EXAMPLE	`n=5: 5th Catalan=42=2.3.7 with 3 distinct factors.`
	CROSSREFS	`Cf. A001221, A000108.` `Adjacent sequences: A080402 A080403 A080404 this_sequence A080406 A080407 A080408` `Sequence in context: A101776 A047745 A121536 this_sequence A039728 A029119 A087823`
	KEYWORD	`nonn`
	AUTHOR	`Labos E. (labos(AT)ana.sote.hu), Mar 19 2003`

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Last modified October 7 14:39 EDT 2008. Contains 144666 sequences.

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