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%I #24 Jul 03 2022 06:47:09
%S 36,100,196,225,256,441,484,676,1089,1156,1225,1444,1521,2116,2601,
%T 3025,3249,3364,3844,4225,4761,5476,5929,6561,6724,7225,7396,7569,
%U 8281,8649,8836,9025,11236,12321,13225,13924,14161,14884,15129
%N Numbers with 9 divisors.
%C Numbers of the form p^8 (8th row of A120458) or p^2*r^2 (A085986), where p and r are distinct primes. - _R. J. Mathar_, Mar 01 2010
%H R. J. Mathar, <a href="/A030627/b030627.txt">Table of n, a(n) for n = 1..1000</a>
%F A000005(a(n)) = 9. - _Juri-Stepan Gerasimov_, Oct 10 2009
%F Sum_{n>=1} 1/a(n) = (P(2)^2 - P(4))/2 + P(8) = 0.0678286..., where P is the prime zeta function. - _Amiram Eldar_, Jul 03 2022
%t Select[Range[90000],DivisorSigma[0,#]==9&] (* _Vladimir Joseph Stephan Orlovsky_, May 05 2011 *)
%o (PARI) is(n)=numdiv(n)==9 \\ _Charles R Greathouse IV_, Jun 19 2016
%Y Cf. A000005, A030515, A030516, A030626, A085986, A120458, A179645.
%K nonn
%O 1,1
%A _Jeff Burch_
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