Base 7 has 6 possible final digits
At 1 digits, there were 3 primes, 0 leaders
At 2 digits, there were 5 primes, 1 leaders
At 3 digits, there were 6 primes, 2 leaders
At 4 digits, there were 4 primes, 3 leaders
At 5 digits, there were 1 primes, 1 leaders
In total, in base 7 there were 19 primes and 7 leaders, maxlen=5