A003960 - OEIS

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A003960

Fully multiplicative with a(p) = [ (p+1)/2 ] for prime p.

1, 1, 2, 1, 3, 2, 4, 1, 4, 3, 6, 2, 7, 4, 6, 1, 9, 4, 10, 3, 8, 6, 12, 2, 9, 7, 8, 4, 15, 6, 16, 1, 12, 9, 12, 4, 19, 10, 14, 3, 21, 8, 22, 6, 12, 12, 24, 2, 16, 9, 18, 7, 27, 8, 18, 4, 20, 15, 30, 6, 31, 16, 16, 1, 21, 12, 34, 9, 24, 12, 36, 4, 37, 19, 18, 10, 24, 14, 40, 3, 16, 21, 42, 8, 27 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,3`
	FORMULA	`If n = Product p(k)^e(k) then a(n) = Product [ (p(k)+1)/2 ]^e(k).` `Multiplicative with a(p^e) = [(p+1)/2]^e. - David W. Wilson (davidwwilson(AT)comcast.net), Aug 01, 2001.`
	CROSSREFS	`Cf. A003970.` `Sequence in context: A136523 A163507 A003963 * A124223 A094193 A108712` `Adjacent sequences: A003957 A003958 A003959 * A003961 A003962 A003963`
	KEYWORD	`nonn,mult`
	AUTHOR	`Marc LeBrun (mlb(AT)well.com)`

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Last modified February 15 19:15 EST 2012. Contains 205852 sequences.