Coin Jam from https://www.go-hero.net/jam/16/name/RX14

gistfile1.txt

$ cat coin_jam.cr 
n = 16
j = 50

max_bound = (2**n - 1).to_u64
min_bound = (max_bound - 2**(n-1) + 2).to_u64

puts "Case #1:"

cur = min_bound
while cur <= max_bound && j > 0
  str = cur.to_s(2)

  divisors = (2..10).map { |base| check_prime(str.to_u64(base)) }
  if divisors.any? &.nil?
    cur += 2
    next
  end

  puts str + ' ' + divisors.join(' ')

  j -= 1
  cur += 2
end

def check_prime(val)
  divisor = 2
  while divisor < 100
    return divisor if val % divisor == 0
    divisor += 1
  end

  nil
end

$ ruby coin_jam.cr 
coin_jam.cr:14: syntax error, unexpected '.'
  if divisors.any? &.nil?
                     ^
coin_jam.cr:23: syntax error, unexpected keyword_end, expecting end-of-input