250073domain: NPropertiesPrimalityPrimeyesAppears in sequences"Ceiling of hypotenuses": a(n) = ceiling(sqrt(a(n-1)^2 + a(n-2)^2)), a(1)=1, a(2)=3.at n=47A104805Each entry is the first of three consecutive primes with equal digital sum.at n=13A209396Prime numbersat n=22054