id:A050338 - OEIS Search Results

Search: id:A050338

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Number of ways of factoring n with 2 levels of parentheses.

+0
3

1, 1, 1, 4, 1, 4, 1, 10, 4, 4, 1, 16, 1, 4, 4, 30, 1, 16, 1, 16, 4, 4, 1, 54, 4, 4, 10, 16, 1, 22, 1, 75, 4, 4, 4, 74, 1, 4, 4, 54, 1, 22, 1, 16, 16, 4, 1, 176, 4, 16, 4, 16, 1, 54, 4, 54, 4, 4, 1, 102, 1, 4, 16, 206, 4, 22, 1, 16, 4, 22, 1, 267, 1, 4, 16, 16, 4, 22, 1, 176, 30, 4, 1, 102 (list; graph; listen)

	OFFSET	`1,4`
	COMMENT	`a(n) depends only on prime signature of n (cf. A025487). So a(24) = a(375) since 24=2^33 and 375=35^3 both have prime signature (3,1).`
	FORMULA	`Dirichlet g.f.: prod{n=2 to inf}(1/(1-1/n^s)^A050336(n)).`
	EXAMPLE	`4=((4))=((22))=((2)(2))=((2))*((2)).`
	CROSSREFS	`Cf. A001055, A050336-A050341. a(p^k)=A007713. a(A002110)=A000307.` `Sequence in context: A095666 A089655 A097936 this_sequence A077088 A156896 A002193` `Adjacent sequences: A050335 A050336 A050337 this_sequence A050339 A050340 A050341`
	KEYWORD	`nonn`
	AUTHOR	`Christian G. Bower (bowerc(AT)usa.net), Oct 15 1999.`

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Last modified December 15 00:47 EST 2009. Contains 170825 sequences.

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