Perfect numbers: Difference between revisions

improved racket example
m (→‎{{header|REXX}}: added/changed comments and whitespace, changed comments in various header and output sections.)
(improved racket example)
Line 1,647:
<lang racket>#lang racket
(require math)
 
(define (perfect? n)
(=
(* n 2)
(sum (divisors n))))
 
; filtering to only even numbers for better performance
(filter perfect? (filter even? (range 100001e5)))
;-> '(0 6 28 496 8128)</lang>
 
Anonymous user