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 A215737 #35 Oct 04 2024 00:24:49
%S A215737 1,1,8,7,6,0,6,0,9,6,6,2,2,7,6,9
%N A215737 a(n) is the first digit to appear n times in succession in a power of 11.
%t A215737 n = 1; x = 1; lst = {};
%t A215737 For[i = 1, i <= 10000, i++,
%t A215737 z = Split[IntegerDigits[x]]; a = Length /@ z; b = Max[a];
%t A215737 For[j = n, j <= b, j++,
%t A215737 AppendTo[lst, First[First[Part[z, First[Position[a, b]]]]]]; n++
%t A215737 ]; x = 11 x ]; lst (* _Robert Price_, Mar 16 2019 *)
%o A215737 (Python)
%o A215737 def A215737(n):
%o A215737 a, s = 1, tuple(str(i)*n for i in range(10))
%o A215737 while True:
%o A215737 a *= 11
%o A215737 t = str(a)
%o A215737 for i, x in enumerate(s):
%o A215737 if x in t:
%o A215737 return i # _Chai Wah Wu_, Mar 30 2021
%Y A215737 Cf. A001020 (powers of 11), A045875, A215731, A215732.
%K A215737 nonn,more,base
%O A215737 1,3
%A A215737 _V. Raman_, Aug 22 2012
%E A215737 a(10)-a(13) added by _V. Raman_, Apr 30 2012, in correspondence with A215731.
%E A215737 a(14) from _Giovanni Resta_, Apr 18 2016
%E A215737 a(15) from _Bert Dobbelaere_, Feb 15 2019
%E A215737 a(16) from _Paul Geneau de Lamarlière_, Oct 03 2024