A068540 - OEIS

%I #19 Jun 24 2022 04:33:59

%S 5,51,171,357,442,582,1071,1250,1292,1460,1746,5456,6435,6825,7248,

%T 8060,8140,8540,9348,9486,9516,9594,9632,9636,10476,10860,10950,12192,

%U 20910,23160,23680,25308,27468,28032,29340,31392,34000,37488,45220,49504,50388,51680

%N Numbers k such that phi(k) = bigomega(k)*tau(k)^2.

%C Conjecture: a(116) = 14137200 is the last term of this sequence (checked up to 10^10). - _Amiram Eldar_, Jun 24 2022

%H Amiram Eldar, <a href="/A068540/b068540.txt">Table of n, a(n) for n = 1..116</a> (terms 1..100 from Harvey P. Dale)

%t Select[Range[46000],EulerPhi[#]==PrimeOmega[#]DivisorSigma[0,#]^2&] (* _Harvey P. Dale_, Jun 06 2021 *)

%Y Cf. A000005, A000010, A001222.

%K easy,nonn

%O 1,1

%A _Benoit Cloitre_, Mar 25 2002