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A034684 If n = p_1^e_1 * ... * p_k^e_k, p_1 < ... < p_k primes, then a(n) = min { p_i^e_i }. 22

%I

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

%T 31,32,3,2,5,4,37,2,3,5,41,2,43,4,5,2,47,3,49,2,3,4,53,2,5,7,3,2,59,3,

%U 61,2,7,64,5,2,67,4,3,2,71,8,73,2,3,4,7,2,79,5,81,2,83,3,5,2,3,8,89,2,7,4

%N If n = p_1^e_1 * ... * p_k^e_k, p_1 < ... < p_k primes, then a(n) = min { p_i^e_i }.

%C a(1) = 1; for n > 1, smallest unitary divisor of n that is larger than 1.

%H T. D. Noe, <a href="/A034684/b034684.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = min{A141809(n,k): k=1..A001221(n)}. - _Reinhard Zumkeller_, Jan 29 2013

%t A034684[n_]:=Min[(#[[1]]^#[[2]])&/@FactorInteger[n]]; Array[A034684,100] (* _Enrique PĂ©rez Herrero_, Nov 01 2011 *)

%o (PARI) A034684(n) = {local(f,m);if(n==1,1,f=factor(n);m=f[1,1]^f[1,2];for(i=1,matsize(f)[1],m=min(m,f[i,1]^f[i,2]));m)} \\ _Michael B. Porter_, Jan 28 2010

%o (Haskell)

%o a034684 = minimum . a141809_row -- _Reinhard Zumkeller_, Jan 29 2013

%Y Cf. A020639, A006530, A034684, A028233, A034699, A053585.

%Y Cf. A034444, A034448, A052125.

%Y Cf. A008475.

%K nonn,nice,easy

%O 1,2

%A _Erich Friedman_

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Last modified October 17 01:30 EDT 2018. Contains 316275 sequences. (Running on oeis4.)