Project Euler Forum

I must be missing something, but why is the first "very odd number" not 315?

7 and 9 occurs 0 times.
"Each digit" means each of the digits 1, 3, 5, 7, 9, and not each digit of the number.

How about adding a link between problem 845 and problem 974.

@ Problem 974: Problem 845 is a similar possibly easier problem; you can try solving that first.
@ Problem 845: Problem 974 is a similar possibly harder problem; you can try solving that after this problem.