## Is the last digit of this number :44n+1 {{4^4}^n}+1 always 77 for n>1n>1 and could this be prime?

Some computations in wolfram alpha for n=2,3,4,5,6 showed that the last digit of this number 44n+1 for n>1 always 7 . My question here :How do I know if it’s last digit always is 7 ? Note: My Goal is to know for which values of n: 44n+1 could be prime ? Thank you for … Read more