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 A308072 #17 May 19 2019 19:44:02 %S A308072 0,1,2,3,4,5,6,7,8,1066338786883726756382,1066338787045067082685, %T A308072 1066338805156287287066,1066338805156287287067,1066338805156287300050, %U A308072 1066338805156301216066,1066341132816741837214,1070235882243468707818,1070235882243470056412,1070236076684636644063 %N A308072 Numbers k such that k is the substring identical to the most significant digits of its base-9 representation. %C A308072 Numbers k whose base-9 representation begins with the same digits as k itself. %H A308072 Scott R. Shannon, <a href="/A308072/b308072.txt">Table of n, a(n) for n = 1..500</a> %e A308072 1066338786883726756382_10 = 10663387868837267563825_9, which also begins with '1066338786883726756382'. %o A308072 (PARI) isok(n) = my(vb=digits(n, 9), vd=digits(n)); vd == vector(#vd, k, vb[k]); \\ _Michel Marcus_, May 17 2019 %Y A308072 This is a subsequence of A228052. %Y A308072 See A181929, A307254, A307255, A307256, A307257, A308070, A308071 for other bases. %K A308072 nonn,base %O A308072 1,3 %A A308072 _Scott R. Shannon_, May 11 2019