A030439 a(n+1) = smallest number not containing any digits of a(n), working in base 3.
0, 1, 2, 3, 8, 9, 26, 27, 80, 81, 242, 243, 728, 729, 2186, 2187, 6560, 6561, 19682, 19683, 59048, 59049, 177146, 177147, 531440, 531441, 1594322, 1594323, 4782968, 4782969, 14348906, 14348907, 43046720, 43046721, 129140162, 129140163, 387420488, 387420489
Offset: 0
Links
- Index entries for linear recurrences with constant coefficients, signature (0, 4, 0, -3).
Formula
3^i-1 then 3^i.
a(n) = 4*a(n-2)-3*a(n-4); g.f.: -x*(x^2-2*x-1) / ((x-1)*(x+1)*(3*x^2-1)). - Colin Barker, Sep 13 2014
a(n) = 3^floor(n/2) -1 +(n mod 2). - Alois P. Heinz, Sep 14 2014