%I #4 Dec 09 2015 20:16:18
%S 0,1,2,0,11,11,0,11,22,0,101,101,0,111,111,0,121,121,0,101,202,0,111,
%T 212,0,121,222,0,1001,1001,0,1001,1001,0,1001,1001,0,1001,1001,0,1111,
%U 1111,0,1111,1111,0,1001,1001,0,1111,1111,0,1221,1221,0,1001,2002,0,1001,2002,0,1001,2002,0,1001,2002,0,1111,2112
%N a(n) = largest base-3 palindrome m <= n such that every base-3 digit of m is <= the corresponding digit of n; m is written in base 3.
%Y Sequences related to palindromic floor and ceiling: A175298, A206913, A206914, A261423, A262038, and the large block of consecutive sequences beginning at A265509.
%K nonn,base
%O 0,3
%A _N. J. A. Sloane_, Dec 09 2015