31378962457domain: NAppears in sequencesa(n) = number of n-digit base-3 biquams.at n=22A064686a(0)=1; a(n) = 3^n - 2^(n-1) for n >= 1.at n=22A083313a(n) = 9^n - (1/2)*4^n, n > 0; a(0) = 0.at n=11A386293