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In prime factorization of n replace all primes with the least prime factor of n; a(1)=1.
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%I #9 Apr 14 2020 13:51:41

%S 1,2,3,4,5,4,7,8,9,4,11,8,13,4,9,16,17,8,19,8,9,4,23,16,25,4,27,8,29,

%T 8,31,32,9,4,25,16,37,4,9,16,41,8,43,8,27,4,47,32,49,8,9,8,53,16,25,

%U 16,9,4,59,16,61,4,27,64,25,8,67,8,9,8,71,32

%N In prime factorization of n replace all primes with the least prime factor of n; a(1)=1.

%C a(n)<=n<=A068795(n);

%C a(n) = A068795(n) iff n=1 or n=p^k for some prime p, k>0.

%C a(30)=a(2*3*5)=2*2*2=8.

%H Harvey P. Dale, <a href="/A068794/b068794.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = A020639(n)^A001222(n).

%t lpf[n_]:=Module[{fi=FactorInteger[n]},Times@@PadRight[{},Total[ fi[[All,2]]], fi[[1,1]]]]; Array[lpf,80] (* _Harvey P. Dale_, Apr 14 2020 *)

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, Mar 05 2002