A030439 - OEIS

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

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OFFSET

0,3

LINKS

Table of n, a(n) for n=0..37.

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

CROSSREFS

Cf. A030283.