Attempting to reproduce a hash-iterate-key bug using hash tables directly rather than sets.

hash-potential-bug.rkt

#lang racket

(require math/number-theory)

(define limit 28123)

(define (is-abundant? n)
  (> (- (apply + (divisors n)) n) n))

(define abundants
  (for/hash ([i (in-range limit)]
             #:when (is-abundant? i))
            (values i #t)))

(define abundants-gen
  (for*/hash ([i (in-hash-keys abundants)]
              [j (in-hash-keys abundants)]
              #:when (and (not (= i j)) (< (+ i j) limit)))
             (values (+ i j) #t)))

(hash-count abundants-gen)
abundants-gen