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a(n) = n*(mu(n)+2), where mu is the Moebius function (A008683).
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%I #8 Apr 21 2021 12:41:27

%S 3,2,3,8,5,18,7,16,18,30,11,24,13,42,45,32,17,36,19,40,63,66,23,48,50,

%T 78,54,56,29,30,31,64,99,102,105,72,37,114,117,80,41,42,43,88,90,138,

%U 47,96,98,100,153,104,53,108,165,112,171,174,59,120,61,186,126,128,195,66

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

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

%H Antti Karttunen, <a href="/A080848/b080848.txt">Table of n, a(n) for n = 1..10000</a>

%o (Scheme) (define (A080848 n) (* n (+ 2 (A008683 n)))) ;; _Antti Karttunen_, Jul 26 2017

%Y Cf. A008683, A080847, A080849.

%K nonn

%O 1,1

%A _Reinhard Zumkeller_, Feb 20 2003