141214768239domain: NAppears in sequencesa(n) = (3^n - 3)/2.at n=23A029858a(0) = 1, a(1) = 3, a(n) = 3*a(n-1) + 3 for n > 1.at n=23A123109Period of the sequence of the digital roots of Fibonacci n-step numbers.at n=22A210456