Wednesday, June 29, 2016

Project Euler 200 prime-proof sqube

We shall define a sqube to be a number of the form, p2q3, where p and q are distinct primes.
For example, 200 = 5223 or 120072949 = 232613.
The first five squbes are 72, 108, 200, 392, and 500.
Interestingly, 200 is also the first number for which you cannot change any single digit to make a prime; we shall call such numbers, prime-proof. The next prime-proof sqube which contains the contiguous sub-string "200" is 1992008.
Find the 200th prime-proof sqube containing the contiguous sub-string "200".

this problem is not hard but for fun~!
hint is generate numbers until 10^13

No comments:

Post a Comment