I get the same answers for n = 9, d = 7 and n = 10, d = 8. It is possible to do it with a lot less computation  my single threaded C++ code took about 3.5s for n = 9, d = 7 and about 32s for n = 10, d = 8. Almost all of the time for n = 10 (like 31.9s) was spent generating a list of 8 digit primes.
Quote:
Originally Posted by Walter
With n = 9, d = 7 I get the following values:
min: 117390
max: 194304
And with n = 10, d = 8:
min: 1747537
max: 1772281
The runtime was about 13000 seconds for the n = 9 case. For the n = 10 case, I used 4 threads, which resulted in a runtime of 12400 seconds.
