Perfect numbers: Difference between revisions

{{trans|D}}

Restricted to the first four perfect numbers as the fifth one is very slow to emerge.

if (n <= 2) return false

var tot = 1

{{libheader|Wren-math}}

This makes use of the fact that all known perfect numbers are of the form <big> (2^''n'' - 1) × 2^{''n'' - 1}</big> where <big> (2^''n'' - 1)</big> is prime and finds the first seven perfect numbers instantly. The numbers are too big after that to be represented accurately by Wren.

 

var isPerfect = Fn.new { |n|