9 lines
220 B
Common Lisp
9 lines
220 B
Common Lisp
;; stern (2n ) = stern (n)
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;; stern(2n+1) = stern(n) + stern(n+1)
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(define (stern n)
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(cond
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(( < n 3) 1)
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((even? n) (stern (/ n 2)))
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(else (let ((m (/ (1- n) 2))) (+ (stern m) (stern (1+ m)))))))
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(remember 'stern)
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