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%I #6 Dec 09 2015 21:41:14
%S 0,1,2,3,3,11,11,11,11,11,22,22,22,22,22,33,33,101,101,101,101,111,
%T 111,111,111,121,121,121,121,131,131,131,131,131,202,202,202,202,212,
%U 212,212,212,222,222,222,222,232,232,232,232,232,303,303,303,303,313,313,313,313,323,323,323,323,333,333,1001,1001
%N Largest base-4 palindrome m <= n, 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