This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A265563 #4 Dec 10 2015 10:51:26 %S A265563 0,1,2,3,11,11,22,22,22,22,22,33,33,33,33,33,101,101,111,111,111,111, %T A265563 121,121,121,121,131,131,131,131,202,202,202,202,202,212,212,212,212, %U A265563 222,222,222,222,232,232,232,232,303,303,303,303,303,313,313,313,313,323,323,323,323,333,333,333,333,1001,1001,1111 %N A265563 Smallest base-4 palindrome m >= n, written in base 4. %Y A265563 Sequences related to palindromic floor and ceiling: A175298, A206913, A206914, A261423, A262038, and the large block of consecutive sequences beginning at A265509. %K A265563 nonn,base %O A265563 0,3 %A A265563 _N. J. A. Sloane_, Dec 10 2015