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%I #8 Sep 28 2019 03:22:04
%S 2,9,15,114,170,175,245,351,372,558,580,625,1012,1032,1375,1377,1450,
%T 1640,2322,3944,4225,4240,4700,4824,5566,5766,5929,6432,6591,6655,
%U 7236,8272,8385,8410,9933,10250,10545,11152,11193,11638,13209,14973,15168
%N Number of divisors of n equals the average of distinct prime factors of n.
%H Amiram Eldar, <a href="/A067547/b067547.txt">Table of n, a(n) for n = 1..10000</a>
%e The prime factors of 15 are 3 and 5, having an average of 4. The number of divisors of 15 is also 4, so 15 is a term of the sequence.
%t f[ n_ ] := FactorInteger[ n ]; g[ n_ ] := Module[ {a, l, t, r}, a = f[ n ]; l = Length[ a ]; t = Table[ a[ [ i ] ][ [ 1 ] ], {i, 1, l} ] ]; Select[ Range[ 2, 10^5 ], Mean[ g[ # ] ] == DivisorSigma[ 0, # ] & ]
%Y Cf. A000005, A323171, A323172.
%K nonn
%O 1,1
%A _Joseph L. Pe_, Jan 28 2002
%E More terms from _Naohiro Nomoto_, Mar 01 2002
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