6 lines
243 B
Text
6 lines
243 B
Text
;; Finding perfect numbers
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(define (sum/inv n) ;; look for div's in [2..sqrt(n)] and add 1/n
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(for/fold (acc (/ n)) [(i (in-range 2 (sqrt n)))]
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#:break (> acc 1) ; no hope
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(when (zero? (modulo n i ))
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(set! acc (+ acc (/ i) (/ i n))))))
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