393977domain: NPropertiesPrimalityPrimeyesAppears in sequences1/2 the number of n X n arrays of squares of integers with every 2X2 subblock summing to 20.at n=15A159221Primes of the form x^2 + 17*y^2, where x and y=x+1 are consecutive natural numbers.at n=28A176622Prime numbersat n=33398