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A143408 Number of numbers k such that the reduced totient function psi(k) = A002174(n). +0
5
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; listen)
OFFSET

1,1

COMMENT

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 this_sequence A088915 A084790 A130237

Adjacent sequences: A143405 A143406 A143407 this_sequence A143409 A143410 A143411

KEYWORD

nonn

AUTHOR

T. D. Noe (noe(AT)sspectra.com), Aug 13 2008

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Last modified December 17 13:29 EST 2009. Contains 170826 sequences.


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