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 A215733 #25 Nov 09 2024 14:48:15 %S A215733 1,7,8,5,5,8,2,1,2,2,2,4,5,8,2,4,4 %N A215733 a(n) is the first digit to appear n times in succession in a power of 3. %o A215733 (Python) %o A215733 def A215733(n): %o A215733 l, x = [str(d)*n for d in range(10)], 1 %o A215733 for m in range(10**9): %o A215733 s = str(x) %o A215733 for k in range(10): %o A215733 if l[k] in s: %o A215733 return k %o A215733 x *= 3 %o A215733 return 'search limit reached' %o A215733 # _Chai Wah Wu_, Dec 17 2014 %Y A215733 Cf. A215727, A045875, A215732. %K A215733 nonn,base,more %O A215733 1,2 %A A215733 _V. Raman_, Aug 22 2012 %E A215733 a(12) from _Chai Wah Wu_, Dec 17 2014 %E A215733 a(13)-a(14) from _Giovanni Resta_, Apr 20 2016 %E A215733 a(15) from _Bert Dobbelaere_, Mar 04 2019 %E A215733 a(16)-a(17) from _Bert Dobbelaere_, Mar 20 2019