1259604domain: NAppears in sequencesa(n) = (4*n-1)*4*n*(4*n+1).at n=27A069140p*(p+1)*(p+2) where (p,p+2) are twin primes.at n=9A126248Area of the unique primitive Pythagorean triple whose inradius is the n-th odd prime and whose short leg is an even number.at n=26A380302