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 A074344 #8 Oct 31 2013 12:17:21
%S A074344 8,9,23,51,69,81,93,129,169,179,181,273,321,323,471,493,633,689,781,
%T A074344 933,951,969,1229,1309,1509,1707,1821,1863,1913,2169,2337,2433,3259,
%U A074344 3513,3681,3921,4431,4611,5043,5091,5361,5409,6231,6471,6999,7757,7963,8283
%N A074344 a(1) = 8; a(n) is smallest number > a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.
%t A074344 a[1] = 8; 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 A074344 Cf. A046258, A069610, A074336, A074338, A074339, A074340, A074341, A074342, A074343, A074345, A074346.
%K A074344 nonn,base
%O A074344 1,1
%A A074344 _Zak Seidov_, Sep 23 2002
%E A074344 Corrected and extended by _Robert G. Wilson v_, Aug 05 2005