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 A074343 #8 Oct 31 2013 12:17:21
%S A074343 7,9,19,27,47,57,61,81,179,211,251,273,373,477,581,753,847,909,971,
%T A074343 1399,1623,1967,2139,2629,2979,3297,3393,3647,3793,4281,4337,4411,
%U A074343 4517,4831,4979,5131,5841,5897,5953,5991,6287,6309,8101,8147,8521,8877,8969,9699
%N A074343 a(1) = 7; a(n) is smallest number > a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.
%t A074343 a[1] = 7; 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, 48}] (* _Robert G. Wilson v_ *)
%Y A074343 Cf. A046257, A069609, A074336, A074338, A074339, A074340, A074341, A074342, A074344, A074345, A074346.
%K A074343 nonn,base
%O A074343 1,1
%A A074343 _Zak Seidov_, Sep 23 2002
%E A074343 More terms from _Robert G. Wilson v_, Aug 05 2005