A144862 Composite numbers n such that sqrt(n) > f(n), where f(n) = 2 * rad(n) if 4 divides n and rad(n) otherwise.

27, 32, 54, 64, 81, 125, 128, 162, 192, 216, 243, 250, 256, 288, 324, 343, 375, 384, 405, 432, 486, 500, 512, 567, 576, 625, 640, 648, 675, 686, 729, 768, 800, 864, 896, 972, 1000, 1024, 1029, 1125, 1152, 1215, 1250, 1280, 1296, 1323, 1331, 1350, 1372, 1458

Offset

1,1

Comments

Subset of A144100.

Links

Table of n, a(n) for n=1..50.

Prog

(PARI) rad(n) = local(p); p=factor(n)[, 1]; prod(i=1, length(p), p[i]) ;
ff(n) = if ((n % 4)==0 , 2*rad(n), rad(n)); isok(n) = (n != 1) && (! isprime(n)) && (n > ff(n)^2); \\ Michel Marcus, Aug 09 2013

Crossrefs

Cf. A000040, A007947, A144100.

Sequence in context: A324248 A275188 A198147 * A117934 A173136 A030134

Adjacent sequences: A144859 A144860 A144861 * A144863 A144864 A144865

Keyword

easy,nonn

Author

Reikku Kulon, Sep 23 2008

Status

approved