15904350domain: NAppears in sequencesa(1) = a(2) = 0; a(3) = 2; for n >= 4, a(n) = (prime(n-1)-2)*a(n-1), where prime(n) is the n-th prime.at n=9A121406Column k=1 of Brent's table A381083 related to prime gaps 2n.at n=23A381084Column k=1 of Brent's table A381083 related to prime gaps 2n.at n=26A381084