A114071 sigma(n) + n is a fourth power.
33, 7153, 16065, 29976, 36673, 39169, 117985, 849385, 2475045, 2757073, 5421336, 7137025, 9474784, 10797120, 11596833, 13627248, 15714240, 25586785, 26821458, 28849249, 37001785, 40441441, 43751896, 69748561, 70338768, 95516836
Offset: 1
Keywords
Examples
sigma(33) + 33 = 81 = 3^4.
Programs
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PARI
isok(n) = ispower(sigma(n) + n, 4); \\ Michel Marcus, Jan 09 2014
Extensions
a(9)-a(26) from Donovan Johnson, Feb 01 2009