205633domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumber of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, -1, 0), (0, 1, -1), (1, 0, 1), (1, 1, 1)}.at n=9A150737Primes p such that (p-1)/2 and p+1 have the same sum of divisors.at n=2A249625Prime numbersat n=18439