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sigma(n) + n is a fourth power.
0

%I #7 Jan 09 2014 11:20:52

%S 33,7153,16065,29976,36673,39169,117985,849385,2475045,2757073,

%T 5421336,7137025,9474784,10797120,11596833,13627248,15714240,25586785,

%U 26821458,28849249,37001785,40441441,43751896,69748561,70338768,95516836

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

%e sigma(33) + 33 = 81 = 3^4.

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

%Y Cf. A155085, subsequence of A114069.

%K nonn

%O 1,1

%A _Giovanni Resta_, Feb 13 2006

%E a(9)-a(26) from _Donovan Johnson_, Feb 01 2009