[racket] what's wrong with my code?

For one thing, the question you are asking in the code,
	(> i 4)  ;; i.e., i > 4
is not the same question you ask in your equations,
	n < 4
so, for starters, it would seem you need the two questions to be in agreement.

Best,
jmj 
-- 
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Robert Hume <rhume55 at gmail.com> wrote:

>I'm really stuck trying to figure this out.  Any pointers are useful!
>Here's the problem:
>
>f(n) = n if n<4
>and
>f(n) = f(n - 1) + 2f(n - 2) + 3f(n - 3) + 4f(n - 4) if n>= 4
>
>Here's my solution so far -- any one know what I'm doing wrong?
>
>(define (f n)
>
>  (define (f-iter result i)
>    (if (> i 4)
>        result
>        (f-iter (+ result (* i (- n i))) (+ i 1))
>    )
>  )
>
>  (if (< n 4)
>      n
>      (f-iter 0 1)
>  )
>
>)
>
>(f 4) ;; should produce 10, produces 10
>(f 5) ;; should produce 26, produces 20
>(f 6) ;; should produce 63, produces 30
>
>
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>
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