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 A084673 #15 Jan 01 2017 19:09:37
%S A084673 2,11,1117,10111,101111,1111151,11110111,101111111,1111111121,
%T A084673 11111111113,101111111111,1111111118111,11111111111411,
%U A084673 111111111116111,1111111111111181,11111111101111111,101111111111111111
%N A084673 Smallest prime in which a digit appears n times.
%C A084673 For n > 1, conjectured to be equal to A037055(n), the smallest prime in { R-10^n, R-10^(n-1), ..., R-10; R+a*10^b, a = 1, ..., 8, b = 0, 1, 2, ..., n }, where R = (10^(n+1)-1)/9 is the (n+1)-digit repunit. - _M. F. Hasler_, Feb 25 2016
%D A084673 Liz Strachan, Numbers are Forever, Mathematical Facts and Curiosities, Constable, London, 2014, page 267.
%H A084673 Robert G. Wilson v, <a href="/A084673/b084673.txt">Table of n, a(n) for n = 1..1000</a>
%e A084673 a(4)=10111 because 10111 is the smallest prime with four duplicate digits.
%t A084673 Table[ First[ Select[ Prime[ Range[100000]], Max[ DigitCount[ # ]]==i & ]], {i, 6}] (* or *)
%t A084673 f[n_, b_] := Block[{k = 10^(n + 1), p = Permutations[ Join[ Table[ b, {i, 1, n}], {x}]], c = Complement[ Table[j, {j, 0, 9}], {b}], q = {}}, Do[q = Append[q, Replace[p, x -> c[[i]], 2]], {i, 1, 9}]; r = Min[ Select[ FromDigits /@ Flatten[q, 1], PrimeQ[ # ] & ]]; If[ r != Infinity, r, While[ !PrimeQ[k] || Count[ IntegerDigits[k], b] != n, k++ ]; k]]; Table[ f[n, 1], {n, 2, 18}]
%o A084673 (PARI) A084673(n)=if(n>1,A037055(n),2) \\ _M. F. Hasler_, Feb 25 2016
%Y A084673 Cf. A034388, A037055, A065584, A065821.
%K A084673 nonn,base
%O A084673 1,1
%A A084673 _Harvey P. Dale_, Jun 29 2003
%E A084673 Edited and extended by _Robert G. Wilson v_, Jul 03 2003