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e-Perfect Number

A number n is called an e-perfect number if sigma_e(n)=2n, where sigma_e(n) is the sum of the e-Divisors of n. If m is squarefree, then sigma_e(m)=m. As a result, if n is e-perfect and m is squarefree with m_|_n, then mn is e-perfect.

The first few e-perfect numbers are 36, 180, 252, 396, 468, ... (Sloane's A054979). There are no odd e-perfect numbers. The first few primitive e-perfect numbers are 36, 1800, 2700, 17424, ... (Sloane's A054980).

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