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Positive integers not divisible by any of their own prime-factorization exponents.
4

%I #18 Jul 14 2020 10:47:38

%S 1,8,9,25,32,49,64,81,121,125,128,169,225,243,289,343,361,441,512,529,

%T 625,729,841,961,1000,1024,1089,1225,1331,1369,1521,1681,1849,2025,

%U 2048,2187,2197,2209,2401,2601,2744,2809,3025,3249,3481,3721,3969,4096,4225

%N Positive integers not divisible by any of their own prime-factorization exponents.

%C If n>1 is a term then n is composite and is not squarefree. - _Farideh Firoozbakht_, Dec 08 2006

%H Amiram Eldar, <a href="/A124184/b124184.txt">Table of n, a(n) for n = 1..10000</a>

%e 18225 = 3^6 * 5^2. Neither 6 nor 2 divides 18225, so 18225 is in the sequence.

%t f[n_] := Times @@ Mod[n, Last /@ FactorInteger[n]] > 0;Select[Range[5000], f] (* _Ray Chandler_, Dec 06 2006 *)

%t Do[a = FactorInteger[n]; l = Length[a]; b = Table[a[[k]][[2]], {k, l}]; If[ ! MemberQ[Mod[n, b], 0], Print[n]], {n, 4000}] (* _Farideh Firoozbakht_, Dec 08 2006 *)

%Y Cf. A124438.

%K nonn

%O 1,2

%A _Leroy Quet_, Dec 05 2006

%E Extended by _Ray Chandler_ and _Zak Seidov_, Dec 06 2006