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 A353142 #18 Apr 27 2022 19:47:33 %S A353142 0,1,102,11010,1112011,120020112,12122102020,2002110011021, %T A353142 202220111120122,21202002000210100,2212102202021220101, %U A353142 1001200100111221000202,101121210112011021021110,10221012222020120200202111,1110100012201102210221120212 %N A353142 Decimal repunits written in base 3. %F A353142 a(n) = A007089(A002275(n)). %F A353142 a(n) = (A055474(n) - 1)/100. - _Hugo Pfoertner_, Apr 26 2022 %o A353142 (PARI) a(n) = fromdigits(digits((10^n-1)/9, 3)); %Y A353142 Cf. A002275, A291962, A353143, A353144, A353145, A353146, A353147, A353148. %Y A353142 Cf. A003462, A007089, A055474. %K A353142 nonn,base,easy %O A353142 0,3 %A A353142 _Seiichi Manyama_, Apr 26 2022