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(mu(n)+2)*n^2, where mu is the Moebius function (A008683).
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%I #9 Sep 02 2024 11:09:00

%S 3,4,9,32,25,108,49,128,162,300,121,288,169,588,675,512,289,648,361,

%T 800,1323,1452,529,1152,1250,2028,1458,1568,841,900,961,2048,3267,

%U 3468,3675,2592,1369,4332,4563,3200,1681,1764,1849,3872,4050,6348,2209,4608,4802

%N (mu(n)+2)*n^2, where mu is the Moebius function (A008683).

%C n^2 <= a(n) <= 3*n^2.

%H Antti Karttunen, <a href="/A080849/b080849.txt">Table of n, a(n) for n = 1..5000</a>

%F a(n) = n * A080848(n) = A000290(n) * A080847(n). - _Antti Karttunen_, Jul 26 2017

%t Table[(MoebiusMu[n]+2)n^2,{n,50}] (* _Harvey P. Dale_, Sep 02 2024 *)

%o (Scheme) (define (A080849 n) (* n n (+ 2 (A008683 n)))) ;; _Antti Karttunen_, Jul 26 2017

%Y Cf. A000290, A008683, A080847, A080848.

%K nonn

%O 1,1

%A _Reinhard Zumkeller_, Feb 20 2003