253439domain: NPropertiesPrimalityPrimeyesAppears in sequencesa(n) = a(n-1) + a(n-2) + a(n-3).at n=20A007486Primes p such that (p-n)/(n+1) and (n+1)*p+n are both prime, with n=127.at n=4A152388Prime numbersat n=22310