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A068978 Numbers n such that sum(d|n,tau(d)/d) is an integer where tau(x)=A00005(x). 0
1, 2, 9, 18, 105, 210, 24375, 48750, 133848, 18780741, 18780965 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Also n such that n divides A007429(n)

PROG

(PARI) for(n=1, 20000000, if(denominator(sumdiv(n, d, numdiv(d)/d))==1, print1(n, ", ")))

CROSSREFS

Sequence in context: A191520 A037421 A083423 * A006226 A109298 A075537

Adjacent sequences:  A068975 A068976 A068977 * A068979 A068980 A068981

KEYWORD

nonn

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 06 2002

EXTENSIONS

More terms from Rick L. Shepherd (rshepherd2(AT)hotmail.com), Jun 23 2002

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Last modified February 14 02:57 EST 2012. Contains 205567 sequences.