Project Euler Forum

Okay, I see. I just approached it in a different manner. Thanks. And yes the difference for the correct sequence is indeed <4500.

Why under 5000 for 4-digit sequence?

I am thinking that as a increases, only values of a that are powers of another number will generate duplicates. Would this be a correct assumption? My solution produces matching results for the lower values of n posted in this thread, but I still do not get the correct answer for the problem.

I cannot seem to get the correct answer to this problem. I think I'm using a pretty efficient and logical approach. How can I share this approach with those that have solved the problem in order to get some opinion or feedback as to what might be wrong with my thinking? Without posting spoiler info....

Thank you both for your prompt responses.

Powers of 4: CHECK!
20^14: 22

But... alas...
45^67: 540 (Strangely a transposition of the same digits in Thundre's answer)
94^37: 350

I guess I've got some digging to do.

Thanks again.

I am fairly confident in my algorithm, but am not getting the correct answer. Could someone knock the dust off of their old solution and maybe provide a few digital sums for large values of a and b for me to check my results against?

Thanks!

I am having trouble understanding why my solution works for R(100,10000) and not for R(2000000,1000000000). I am using 64 bit unsigned long variables, which should accommodate 10^18 just fine, any hints?