Prime Cores - The Core of a Prime Number
What's a Prime Core? Take a prime number in binary, then strip off the first and last digits (which, for all primes except 2 are always 1's) then interpret the binary string you have left as an integer, and that's the prime core.
Example, the prime 79 in binary is 1001111 so its core is 00111 which is 7. So using C to represent the prime core operation, we have C(79)=7.
Then here's an interesting question: "when is the core of a prime also a prime?"
Content written and posted by Ken Abbott email@example.com