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A082544 Number of ordered quintuples (a,b,c,d,e) with gcd(a,b,c,d,e)=1 (1<= {a,b,c,d,e} <= n). 2
1, 31, 241, 991, 3091, 7501, 16531, 31711, 57781, 96601, 157651, 240031, 362491, 519961, 739201, 1012441, 1383721, 1822711, 2409241, 3091441, 3966301, 4974751, 6257461, 7680781, 9481681, 11474941, 13916191, 16610371, 19911151, 23435191 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..30.

FORMULA

a(n)=sum(k=1, n, mu(k)*floor(n/k)^5); a(n) is asymptotic to c*n^5 with c=0.9643....

PROG

(PARI) a(n)=sum(k=1, n, moebius(k)*floor(n/k)^5)

CROSSREFS

Cf. A018805 (pairs), A071778 (triples).

Sequence in context: A161747 A059899 A140846 * A173832 A272162 A189923

Adjacent sequences:  A082541 A082542 A082543 * A082545 A082546 A082547

KEYWORD

nonn

AUTHOR

Benoit Cloitre, May 11 2003

STATUS

approved

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Last modified February 26 11:49 EST 2020. Contains 332279 sequences. (Running on oeis4.)