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.
%I A244723 #39 Jul 16 2015 22:38:59 %S A244723 1,8,12,14,16,20,22,24,25,27,28,32,36,40,44,45,46,48,50,52,54,56,60, %T A244723 63,64,68,72,75,76,80,81,84,88,90,92,94,96,99,100,104,108,112,116,117, %U A244723 118,120,124,125,126,128,132,135,136,140,144,147,148,150,152,153,156,160,162,164,166 %N A244723 Nonprimes n such that, mu(n) = mu(phi(n)). %C A244723 Odd terms, with the exception of 1, are not squarefree. - _Torlach Rush_, Jul 22 2014. %C A244723 2*p, where p is an odd prime, is in the sequence iff p is in A088179. - _Robert Israel_, Jul 31 2014 %H A244723 Jens Kruse Andersen, <a href="/A244723/b244723.txt">Table of n, a(n) for n = 1..10000</a> %p A244723 filter:= proc(n) uses numtheory; not(isprime(n)) and mobius(n) = mobius(phi(n)) end proc; %p A244723 select(filter, [$1..1000]); # _Robert Israel_, Jul 31 2014 %t A244723 searchMax = 200; Complement[Select[Range[searchMax], MoebiusMu[#] == MoebiusMu[EulerPhi[#]] &], Prime[Range[PrimePi[searchMax]]]] (* _Alonso del Arte_, Jul 05 2014 *) %t A244723 Select[Range[searchMax], !PrimeQ[#] && MoebiusMu[#] == MoebiusMu[EulerPhi[#]]& ] (* _Zak Seidov_, Jul 31 2014 *) %o A244723 (PARI) %o A244723 for(n=1,10^3,if(!isprime(n)&&moebius(eulerphi(n))==moebius(n),print1(n,", "))) \\ _Derek Orr_, Jul 30 2014 %Y A244723 Cf. A078330, A000010, A008683, A053850, A088179. %K A244723 nonn,easy %O A244723 1,2 %A A244723 _Torlach Rush_, Jul 04 2014