All unitary perfect polynomials over F-2 with at most four distinct irreducible factors
A polynomial A is an element of F-2 [x] is unitary perfect if and only if A = Sigma(d vertical bar A, gcd(d,A/d)=1) d. We find all unitary perfect polynomials of the form (P1P2P3P4a4)-P-a1-P-a2-P-a3 where P-1, ... , P-4 is an element of F-2[x] are irreducible polynomials and a(1) ,..., a(4) are non-negative integers. (C) 2011 Elsevier Ltd. All rights reserved.
polynomials sum of divisors unitary divisors finite fields characteristic 2