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A059376 Jordan function J_3(n). 24
1, 7, 26, 56, 124, 182, 342, 448, 702, 868, 1330, 1456, 2196, 2394, 3224, 3584, 4912, 4914, 6858, 6944, 8892, 9310, 12166, 11648, 15500, 15372, 18954, 19152, 24388, 22568, 29790, 28672, 34580, 34384, 42408, 39312, 50652, 48006, 57096 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

REFERENCES

L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 199, #3.

R. Sivaramakrishnan, "The many facets of Euler's totient. II. Generalizations and analogues", Nieuw Arch. Wisk. (4) 8 (1990), no. 2, 169-187.

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

FORMULA

Multiplicative with a(p^e) = p^(3e)-p^(3e-3). - Vladeta Jovovic, Jul 26 2001

a(n) = sum(d|n, d^3*mu(n/d)). - Benoit Cloitre, Apr 05 2002

Dirichlet generating function: zeta(s-3)/zeta(s). - Franklin T. Adams-Watters, Sep 11 2005

A063453(n) divides a(n). - R. J. Mathar, Mar 30 2011

a(n) = Sum_{k=1..n} GCD(k,n)^3 * Cos(2*Pi*k/n). - Enrique Pérez Herrero, Jan 18 2013

a(n) = n^3*Product_{distinct primes p dividing n} (1-1/p^3). - Tom Edgar, Jan 09 2015

MAPLE

J := proc(n, k) local i, p, t1, t2; t1 := n^k; for p from 1 to n do if isprime(p) and n mod p = 0 then t1 := t1*(1-p^(-k)); fi; od; t1; end; # (with k = 3)

A059376 := proc(n)

    add(d^3*numtheory[mobius](n/d), d=numtheory[divisors](n)) ;

end proc: # R. J. Mathar, Nov 03 2015

MATHEMATICA

JordanJ[n_, k_: 1] := DivisorSum[n, #^k*MoebiusMu[n/#] &]; f[n_] := JordanJ[n, 3]; Array[f, 39]

PROG

(PARI) for(n=1, 120, print1(sumdiv(n, d, d^3*moebius(n/d)), ", "))

(PARI) for (n = 1, 1000, write("b059376.txt", n, " ", sumdiv(n, d, d^3*moebius(n/d))); ) \\ Harry J. Smith, Jun 26 2009

(PARI) seq(n) = dirmul(vector(n, k, k^3), vector(n, k, moebius(k)));

seq(39)  \\ Gheorghe Coserea, May 11 2016

CROSSREFS

See A059379 and A059380 (triangle of values of J_k(n)), A000010 (J_1), A007434 (J_2), A059377 (J_4), A059378 (J_5).

Sequence in context: A063578 A063159 A274268 * A206481 A049453 A231888

Adjacent sequences:  A059373 A059374 A059375 * A059377 A059378 A059379

KEYWORD

nonn,mult

AUTHOR

N. J. A. Sloane, Jan 28 2001

STATUS

approved

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Last modified December 3 12:46 EST 2016. Contains 278734 sequences.