A172422 - OEIS

%I #9 Sep 04 2023 15:26:54

%S 256,512,1024,2048,4096,6561,8192,16384,19683,32768,59049,65536,

%T 131072,177147,262144,294912,314928,331776,354294,373248,390625,

%U 393216,419904,442368,472392,497664,524288,531441,559872,589824,629856,663552,708588,746496,786432

%N Numbers k that have measure of smoothness J larger than 7, where J = log(k)/log(rad(k)) and rad(k) is the product of the distinct prime divisors of k (A007947).

%C This sequence is a subsequence of A049094, A172418, A172419, A172420, and A172421.

%H Amiram Eldar, <a href="/A172422/b172422.txt">Table of n, a(n) for n = 1..500</a>

%t aa = {}; Do[kk = FactorInteger[c]; nn = 1; Do[nn = nn*kk[[n]][[1]], {n, 1, Length[kk]}]; If[Log[c]/Log[nn] > 7, AppendTo[aa, c]], {c, 2, 10000}]; aa

%Y Cf. A007947, A049094, A059172, A172418, A172419, A172420, A172421.

%K nonn

%O 1,1

%A _Artur Jasinski_, Feb 02 2010

%E More terms from _Amiram Eldar_, Mar 10 2020