Happy Primes Are SO Much Fun

In the episode 42 when the Doctor babbles on about happy primes I tried it and it works!! I'm so happy I have the first few numbers of the squence here: 1, 7, 13, 19, 23, 31. 

It's so much fun to work out here is an example:

7^2 = 49
4^2 + 9^2 = 97
9^2 + 7^2 = 130
1^2 + 3^2 + 0^2 = 10
1^2 + 0^2 = 1 

And if you don't remember the Doctor's 100 MPH ramble here is a rough copy without copying the Doctor word for word:

Any number that reduces to the 1 when you take the sum of the square roots of its digits and continually trace it  is happy and number that doesn't is unhappy, a happy prime is both happy and prime. 

(And now you know why I get on my math teacher's nerves)