A265514 - OEIS

%I #4 Dec 09 2015 20:22:29

%S 0,1,2,3,0,11,11,11,0,11,22,22,0,11,22,33,0,101,101,101,0,111,111,111,

%T 0,121,121,121,0,131,131,131,0,101,202,202,0,111,212,212,0,121,222,

%U 222,0,131,232,232,0,101,202,303,0,111,212,313,0,121,222,323,0,131,232,333,0,1001,1001,1001,0,1001,1001,1001,0

%N a(n) = largest base-4 palindrome m <= n such that every base-4 digit of m is <= the corresponding digit of n; m is written in base 4.

%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