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A076998 Difference between cubefree and squarefree components of n. 3
0, 0, 0, 2, 0, 0, 0, 2, 6, 0, 0, 6, 0, 0, 0, 2, 0, 12, 0, 10, 0, 0, 0, 6, 20, 0, 6, 14, 0, 0, 0, 2, 0, 0, 0, 30, 0, 0, 0, 10, 0, 0, 0, 22, 30, 0, 0, 6, 42, 40, 0, 26, 0, 12, 0, 14, 0, 0, 0, 30, 0, 0, 42, 2, 0, 0, 0, 34, 0, 0, 0, 30, 0, 0, 60, 38, 0, 0, 0, 10, 6, 0, 0, 42, 0, 0, 0, 22, 0, 60, 0, 46 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..65537

FORMULA

a(n) = A007948(n) - A007947(n). - Antti Karttunen, Jul 21 2018

EXAMPLE

a(4)=2 as cubefree(4)=4 and squarefree(4)=2. 4-2=2

PROG

(PARI) rad(n)=local(p, i); p=factor(n)[, 1]; prod(i=1, length(p), p[i])

rad2(n)=local(p, pn, i); p=factor(n)[, 1]; pn=factor(n)[, 2]; prod(i=1, length(p), p[i]^min(2, pn[i]))

for (k=1, 100, print1(rad2(k)-rad(k)", "))

CROSSREFS

Cf. A007947, A007948.

Sequence in context: A151670 A153587 A059286 * A173956 A306078 A284273

Adjacent sequences:  A076995 A076996 A076997 * A076999 A077000 A077001

KEYWORD

nonn

AUTHOR

Jon Perry, Nov 28 2002

STATUS

approved

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Last modified October 17 07:05 EDT 2018. Contains 316276 sequences. (Running on oeis4.)