login
Numbers n such that phi(n) and sigma(n) are simultaneously perfect squares.
2

%I #15 Apr 17 2022 21:51:41

%S 1,170,364,679,5044,5130,5670,5770,8721,8736,9154,9639,9809,14322,

%T 16376,22413,27783,30256,32025,37114,38760,51455,71604,78570,82615,

%U 88392,92004,100821,101153,104168,115430,121056,133569,139954,148568

%N Numbers n such that phi(n) and sigma(n) are simultaneously perfect squares.

%C A subsequence of A011257. - _M. F. Hasler_, Sep 22 2009

%H Donovan Johnson, <a href="/A067781/b067781.txt">Table of n, a(n) for n = 1..5000</a>

%F A067781 = A006532 intersect A039770. - _M. F. Hasler_, Sep 22 2009

%Y Cf. A006532, A011257, A039770.

%K nonn

%O 1,2

%A _Benoit Cloitre_, Feb 07 2002