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%I #13 Jul 26 2017 09:27:04
%S 4,2,2,3,2,4,2,3,3,4,2,3,2,4,4,3,2,3,2,3,4,4,2,3,3,4,3,3,2,2,2,3,4,4,
%T 4,3,2,4,4,3,2,2,2,3,3,4,2,3,3,3,4,3,2,3,4,3,4,4,2,3,2,4,3,3,4,2,2,3,
%U 4,2,2,3,2,4,3,3,4,2,2,3,3,4,2,3,4,4
%N a(n) = mu(n) + 3, where mu is the Mobius function (A008683).
%C If n is a prime or a semiprime, a(n) gives the number of divisors of n.
%H Antti Karttunen, <a href="/A231821/b231821.txt">Table of n, a(n) for n = 1..5000</a>
%H <a href="/index/Eu#epf">Index entries for sequences computed from exponents in factorization of n</a>
%e a(6) = 4; mu(6) + 3 = 1 + 3 = 4.
%p with(numtheory); a:=n->mobius(n)+3; seq(a(n), n=1..100);
%t Table[MoebiusMu[n] + 3, {n, 100}]
%o (PARI) a(n) = moebius(n) + 3; \\ _Michel Marcus_, Nov 14 2013
%o (define (A231821 n) (+ 3 (A008683 n))) ;; _Antti Karttunen_, Jul 26 2017
%Y Cf. A228409.
%Y One more than A080847, two more than A007423.
%K nonn,easy
%O 1,1
%A _Wesley Ivan Hurt_, Nov 13 2013
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