A143408 - OEIS

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A143408

Number of numbers k such that the reduced totient function psi(k) = A002174(n).

2, 6, 12, 16, 4, 8, 84, 32, 40, 32, 8, 20, 20, 64, 8, 480, 80, 48, 12, 8, 160, 20, 16, 4, 8, 1216, 8, 64, 16, 872, 24, 160, 8, 532, 52, 120, 12, 424, 100, 24, 4, 8, 944, 24, 144, 12, 1912, 272, 8, 16, 276, 24, 64, 144, 1856, 20, 96, 1276, 40, 112, 12, 8, 116, 20, 16, 96, 8 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	COMMENTS	`a(n) is the number of divisors of A143407(n) that are not divisors of A143407(r) for r<n.`
	LINKS	`T. D. Noe, Table of n, a(n) for n=1..500`
	EXAMPLE	`Because A002174(5)=8 and psi(k)=8 for k=32,96,160,480, we have a(5)=4.`
	CROSSREFS	`Cf. A002322 (reduced totient function).` `Sequence in context: A152389 A114103 A065154 * A191331 A088915 A084790` `Adjacent sequences: A143405 A143406 A143407 * A143409 A143410 A143411`
	KEYWORD	`nonn`
	AUTHOR	`T. D. Noe (noe(AT)sspectra.com), Aug 13 2008`

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Last modified February 14 23:53 EST 2012. Contains 205689 sequences.