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 A048335 #24 Feb 16 2025 08:32:39
%S A048335 0,1,2,3,4,5,6,7,8,9,10,12,24,36,48,60,72,84,96,108,120,133,266,399,
%T A048335 532,665,798,931,1064,1197,1330,1464,2928,4392,5856,7320,8784,10248,
%U A048335 11712,13176,14640,16105,32210,48315,64420,80525,96630,112735,128840
%N A048335 a(n) in base 11 is a repdigit.
%H A048335 Vincenzo Librandi, <a href="/A048335/b048335.txt">Table of n, a(n) for n = 0..1000</a>
%H A048335 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Repdigit.html">Repdigit</a>
%F A048335 From _Chai Wah Wu_, May 30 2016: (Start)
%F A048335 a(n) = 12*a(n-10) - 11*a(n-20) for n > 19.
%F A048335 G.f.: x*(10*x^9 + 9*x^8 + 8*x^7 + 7*x^6 + 6*x^5 + 5*x^4 + 4*x^3 + 3*x^2 + 2*x + 1)/(11*x^20 - 12*x^10 + 1). (End)
%F A048335 a(n) = (n - 10*floor((n-1)/10))*(11^floor((n+9)/10) - 1)/10. - _Ilya Gutkovskiy_, May 30 2016
%t A048335 Union[Flatten[Table[FromDigits[PadRight[{}, n, d], 11], {n, 0, 50}, {d, 10}]]] (* _Vincenzo Librandi_, Feb 06 2014 *)
%o A048335 (Python)
%o A048335 A048335_list = [0] + [int(d*l,11) for l in range(1,10) for d in '123456789a'] # _Chai Wah Wu_, May 30 2016
%Y A048335 Cf. A010785, A033024, A028987, A028988.
%K A048335 nonn,base,easy
%O A048335 0,3
%A A048335 _Patrick De Geest_, Feb 15 1999