text: By definition , a perfect number is a fixed point of the restricted divisor function s ( n ) = Ï ( n ) â ' n , and the aliquot sequence associated with a perfect number is a constant sequence .
simplified: By definition , a perfect number is a fixed point of the restricted sum-of-divisors function s ( n ) = Ï ( n ) â ' n , and the aliquot sequence associated with a perfect number is a constant sequence .