344373767domain: NAppears in sequencesa(n) = n*9^n - 1.at n=7A064755a(n) = 8*3^n - 1.at n=16A198644a(n) = 8*9^n-1.at n=8A198966Numbers that can be written as 2*a^2 - 1 and 3*b^3 - 1.at n=9A345702