A172419 - OEIS

A172419

Numbers k that have measure of smoothness J larger than 4, where J = log(k)/log(rad(k)) and rad(k) is the product of the distinct prime divisors of k (A007947).

32, 64, 128, 243, 256, 512, 729, 1024, 1458, 1536, 1728, 1944, 2048, 2187, 2304, 2592, 2916, 3072, 3125, 3456, 3888, 4096, 4374, 4608, 5184, 5832, 6144, 6561, 6912, 7776, 8192, 8748, 9216, 10240, 10368, 11664, 12288, 12500, 12800, 13122, 13824, 15552

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OFFSET

1,1

COMMENTS

Subsequence of A049094 and A172418.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

MATHEMATICA

aa = {}; Do[kk = FactorInteger[c]; nn = 1; Do[nn = nn*kk[[n]][[1]], {n, 1, Length[kk]}]; If[Log[c]/Log[nn] > 4, AppendTo[aa, c]], {c, 2, 10000}]; aa

CROSSREFS

Cf. A007947, A049094, A172418, A172420, A172421, A172422.

Sequence in context: A174312 A255995 A144908 * A069492 A076469 A256819

Adjacent sequences: A172416 A172417 A172418 * A172420 A172421 A172422

KEYWORD

nonn

AUTHOR

Artur Jasinski, Feb 02 2010

STATUS

approved