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%I #11 Mar 31 2017 21:27:24
%S 1,2,3,3,5,6,7,5,5,10,11,9,13,14,15,7,17,10,19,15,21,22,23,15,7,26,7,
%T 21,29,30,31,11,33,34,35,15,37,38,39,25,41,42,43,33,25,46,47,21,11,14,
%U 51,39,53,14,55,35,57,58,59,45,61,62,35,13,65,66,67,51,69,70,71,25,73,74
%N In canonical prime-factorization of n replace prime(k)^e with prime(k+e-1).
%C a(n)<=n; a(n)=n iff n is a squarefree number: a(A005117(n))=A005117(n) and a(A013929(n)) < A013929(n);
%C A099209 = a(a(n)).
%e a(75) = a(3^1 * 5^2) =
%e A000040(A049084(3)+1-1)*A000040(A049084(5)+2-1) =
%e A000040(2+1-1)*A000040(3+2-1) = A000040(2)*A000040(4) = 3*7 = 21.
%t a[n_] := Times @@ (FactorInteger[n] /. {p_Integer, e_Integer} -> Prime[ PrimePi[p] + e - 1]); a[1] = 1; Array[a, 100] (* _Jean-François Alcover_, Dec 07 2016 *)
%K nonn,mult
%O 1,2
%A _Reinhard Zumkeller_, Oct 05 2004
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