For example, 17 is the smallest odd quartan prime: 14 + 24 = 1 + 16 = 17.
With the exception of 2 (x = y = 1), one of x and y will be odd, and the other will be even. If both are odd or even, the resulting integer will be even, and 2 is the only even prime.
The first few quartan primes are
- Neil Sloane, A Handbook of Integer Sequences, Academic Press, NY, 1973.