A172422 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).

256, 512, 1024, 2048, 4096, 6561, 8192, 16384, 19683, 32768, 59049, 65536, 131072, 177147, 262144, 294912, 314928, 331776, 354294, 373248, 390625, 393216, 419904, 442368, 472392, 497664, 524288, 531441, 559872, 589824, 629856, 663552, 708588, 746496, 786432

Offset: 1

Author

Artur Jasinski, Feb 02 2010

Keywords

• nonn

Comments

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

Links

• Amiram Eldar, Table of n, a(n) for n = 1..500

Crossrefs

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

Programs

Mathematica

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

Extensions

More terms from Amiram Eldar, Mar 10 2020