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A075795 Number of k, 0<k<=n, such that the resultant of the k-th cyclotomic polynomial and the n-th cyclotomic polynomial is equal to 1. 0
0, 0, 1, 1, 3, 3, 5, 4, 6, 7, 9, 8, 11, 11, 12, 11, 15, 14, 17, 16, 18, 19, 21, 19, 22, 23, 23, 24, 27, 2, 6, 29, 26, 30, 31, 32, 31, 35, 35, 36, 35, 39, 38, 41, 40, 41, 43, 45, 42, 46, 46, 48, 48, 51, 49, 52, 51, 54, 55, 57, 55, 59, 59, 59, 57, 62, 62, 65, 64, 66, 66, 69, 66, 71 (list; graph; refs; listen; history; internal format)
OFFSET

1,5

COMMENTS

a(n)>=phi(n) since if (k,n)=1, then res(polcyclo(n),polcyclo(k))=1.

REFERENCES

Apostol, T. M. "Resultants of Cyclotomic Polynomials." Proc. Amer. Math. Soc. 24, 457-462, 1970.

Apostol, T. M. "The Resultant of the Cyclotomic Polynomials and ..." Math. Comput. 29, 1-6, 1975.

LINKS

E. M. Weisstein, Cyclotomic polynomials

FORMULA

a(n) = n-A073093(n)

PROG

(PARI) a(n)=sum(k=1, n, if(1-polresultant(polcyclo(n), polcyclo(k)), 0, 1))

CROSSREFS

Cf. A054372, A073093.

Sequence in context: A131950 A116192 A090104 * A058268 A087851 A087852

Adjacent sequences:  A075792 A075793 A075794 * A075796 A075797 A075798

KEYWORD

nonn

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr), Oct 13 2002

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Last modified February 14 17:06 EST 2012. Contains 205644 sequences.