A prism.
So far there has been no formulas found. The randomness of prime numbers make them unpredictable to calculate. There is a bit of a hit and miss formula, which is (2 to the power of p) - 1, with p being a prime number. Prime numbers that fit this are callled "Mersenne primes". Mathematicians are still searching for a formula that works 100% of the time though. =)
Hexagon :P
polygons perhaps
Numbuh 2's name is Hoagie P. Gilligan.
Piccaso
Leonid Pasternak, Andrew Pavlovsky, Vasily Perov and Vasily Polenov are famous Russian artists. Their last name begins with the letter P.
William P. Quinn
Physician is another name for a doctor of medicine. It begins with the letter P.
larrisa latyina :P
Pearl Bailey is a famous singer, actress and entertainer. Colin Powell is a famous politician, administrator and former soldier. Floyd Patterson is a famous retired boxer.
performer
Prague
Pine st.
The pronghorn.
There's the Packers
POE