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 A074339 #10 Mar 15 2015 21:05:44
%S A074339 3,7,9,51,57,103,119,121,183,293,301,351,447,479,577,741,839,1051,
%T A074339 1277,1431,1633,1877,2043,2251,2303,2659,2937,3447,3897,3969,4059,
%U A074339 4179,4371,4389,4563,4841,4903,5097,5103,5369,5689,6621,6831,6927,7479,9227,9351
%N A074339 a(1) = 3; a(n) is smallest number > a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.
%t A074339 a[1] = 3; a[n_] := a[n] = Block[{k = a[n - 1] + 1 + Mod[a[n - 1], 2], c = IntegerDigits @ Table[ a[i], {i, n - 1}]}, While[ !PrimeQ[ FromDigits @ Flatten @ Append[c, IntegerDigits[k]]], k += 2]; k]; Table[ a[n], {n, 47}] (* _Robert G. Wilson v_ *)
%Y A074339 Cf. A069605, A033681, A074336, A074338, A074340, A074341, A074342, A074343, A074344, A074345, A074346.
%K A074339 nonn,base
%O A074339 1,1
%A A074339 _Zak Seidov_, Sep 23 2002
%E A074339 More terms from _Robert G. Wilson v_, Aug 05 2005