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.

A070226 Numbers n such that the squarefree kernel of n is equal to the number of divisors of n.

This page as a plain text file.
%I A070226 #14 Dec 15 2017 17:35:52
%S A070226 1,2,9,12,18,80,448,625,720,1200,1250,1620,2025,4032,4050,5625,7500,
%T A070226 9408,11250,11264,20412,35721,53248,71442,101376,117649,235298,280000,
%U A070226 371712,479232,768320,907200,1058841,1114112,1270080,1411788,1750000
%N A070226 Numbers n such that the squarefree kernel of n is equal to the number of divisors of n.
%C A070226 Numbers n such that A007947(n)/A000005(n) = 1. [From _Ctibor O. Zizka_, Feb 05 2009]
%C A070226 Conjecture : If A000005(n) divides A007947(n) for some n, then A007947(n)=A000005(n). [From _Ctibor O. Zizka_, Feb 05 2009]
%H A070226 Donovan Johnson, <a href="/A070226/b070226.txt">Table of n, a(n) for n = 1..150</a>
%t A070226 Select[Range[2000000],DivisorSigma[0,#]==Times@@Transpose[ FactorInteger[#]][[1]]&] (* _Harvey P. Dale_, Apr 09 2012 *)
%Y A070226 Cf. A007947, A000005, A033950.
%K A070226 nonn
%O A070226 1,2
%A A070226 _Jason Earls_, May 07 2002