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A063885
z(sigma(n)) = 2n, where z(n) =
A048146
.
1
24, 1536, 1631, 47360, 82458
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OFFSET
1,1
LINKS
Table of n, a(n) for n=1..5.
PROG
(PARI) u(n) = sumdiv(n, d, if(gcd(d, n/d)==1, d));
z(n) = sigma(n)-u(n);
for(n=1, 10^7, if(z(sigma(n))==2*n, print1(n, ", ")))
CROSSREFS
Cf.
A000203
,
A034448
,
A048146
,
A019284
.
Sequence in context:
A035174
A288955
A203973
*
A019284
A333042
A112389
Adjacent sequences:
A063882
A063883
A063884
*
A063886
A063887
A063888
KEYWORD
nonn
,
more
AUTHOR
Jason Earls
, Aug 28 2001
STATUS
approved
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Last modified May 11 06:34 EDT 2024. Contains 372388 sequences. (Running on oeis4.)