A114068 - OEIS

%I #8 Jan 09 2014 11:43:09

%S 110,125,609,2047,4895,9819,10149,10367,18974,31269,37032,40662,42032,

%T 44238,44835,48125,51459,51535,52487,77425,90090,116633,129846,137865,

%U 145299,146566,151438,159565,161614,162334,207710,307327,357116

%N sigma(n) + phi(n) is a fourth power.

%H Donovan Johnson, <a href="/A114068/b114068.txt">Table of n, a(n) for n = 1..1000</a>

%e sigma(110) + phi(110) = 256 = 4^4.

%o (PARI) isok(n) = ispower(sigma(n) + eulerphi(n), 4); \\ _Michel Marcus_, Jan 09 2014

%Y Cf. A065387, subsequence of A062784.

%K nonn

%O 1,1

%A _Giovanni Resta_, Feb 13 2006