cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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

This page as a plain text file.
%I A144862 #6 Aug 09 2013 02:56:51
%S A144862 27,32,54,64,81,125,128,162,192,216,243,250,256,288,324,343,375,384,
%T A144862 405,432,486,500,512,567,576,625,640,648,675,686,729,768,800,864,896,
%U A144862 972,1000,1024,1029,1125,1152,1215,1250,1280,1296,1323,1331,1350,1372,1458
%N A144862 Composite numbers n such that sqrt(n) > f(n), where f(n) = 2 * rad(n) if 4 divides n and rad(n) otherwise.
%C A144862 Subset of A144100.
%o A144862 (PARI) rad(n) = local(p); p=factor(n)[, 1]; prod(i=1, length(p), p[i]) ;
%o A144862 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
%Y A144862 Cf. A000040, A007947, A144100.
%K A144862 easy,nonn
%O A144862 1,1
%A A144862 _Reikku Kulon_, Sep 23 2008