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 A111525 #7 Dec 15 2017 17:37:02
%S A111525 10,1,3,3,3,29,1,3,3,11,9,7,23,61,11,3,91,137,7,11,31,93,17,9,273,51,
%T A111525 397,9,99,41,111,129,111,801,109,131,297,37,621,21,807,143,87,57,231,
%U A111525 187,53,169,77,613,867,41,199,773,523,227,27,499,171,329,67,483,393,179
%N A111525 a(1) = 10; a(n) = smallest number such that the juxtaposition a(1)a(2)...a(n) is a prime.
%t A111525 a[1] = 10; a[n_] := a[n] = Block[{k = 1, c = IntegerDigits @ Table[ a[i], {i, n - 1}]}, While[ !PrimeQ[ FromDigits @ Flatten @ Append[c, IntegerDigits[k]]], k += 2]; k]; Table[ a[n], {n, 63}]
%Y A111525 Cf. A111524, A074346, A092528, A069603, A069605, A069606, A069607, A069608, A069609, A069610, A069611, A111525.
%K A111525 base,nonn
%O A111525 1,1
%A A111525 _Amarnath Murthy_, _Jason Earls_ and _Robert G. Wilson v_, Aug 05 2005