0. #lang racket
1.  
2. (define (calculate-generations runs first-gen-prob)
3.  
4.   (define (next-gen current-gen-prob)
5.     (let ((p (first current-gen-prob))
6.           (q (second current-gen-prob)))
7.       (letrec ((a1a1 (* p p))
8.                (a1a2 (* 2 p q))
9.                (a2a2 (* q q))
10.                (result
11.                 (format "a1a1: ~a a1a2: ~a a2a2: ~a\n" a1a1 a1a2 a2a2)))
12.         (display result)
13.         (unless (equal? (+ a1a1 a1a2 a2a2) 1.0)
14.           (error "Misscalculation of Hardy-Weinberg frequencies."))
15.         (list p q))))
16.  
17.   (when (> runs 0)
18.     (begin
19.       (display (format "generation ~a\n" runs))
20.       (calculate-generations (- runs 1) (next-gen first-gen-prob)))))
21.  
22. (define a1a1 0.15)
23. (define a2a2 0.35)
24. (define a1a2 (- 1 (+ a1a1 a2a2)))
25.  
26. (define p (+ a1a1 (/ a1a2 2)))
27. (define q (- 1 p))
28.  
29. (define first-gen-prob (list p q))
30. (calculate-generations 12 first-gen-prob)

=>

generation 12 a1a1: 0.16000000000000003 a1a2: 0.48 a2a2: 0.36 generation 11 a1a1: 0.16000000000000003 a1a2: 0.48 a2a2: 0.36 generation 10 a1a1: 0.16000000000000003 a1a2: 0.48 a2a2: 0.36 generation 9 a1a1: 0.16000000000000003 a1a2: 0.48 a2a2: 0.36 generation 8 a1a1: 0.16000000000000003 a1a2: 0.48 a2a2: 0.36 generation 7 a1a1: 0.16000000000000003 a1a2: 0.48 a2a2: 0.36 generation 6 a1a1: 0.16000000000000003 a1a2: 0.48 a2a2: 0.36 generation 5 a1a1: 0.16000000000000003 a1a2: 0.48 a2a2: 0.36 generation 4 a1a1: 0.16000000000000003 a1a2: 0.48 a2a2: 0.36 generation 3 a1a1: 0.16000000000000003 a1a2: 0.48 a2a2: 0.36 generation 2 a1a1: 0.16000000000000003 a1a2: 0.48 a2a2: 0.36 generation 1 a1a1: 0.16000000000000003 a1a2: 0.48 a2a2: 0.36