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 A069608 #17 Jun 01 2021 08:08:31
%S A069608 6,1,3,1,41,19,17,1,81,27,89,3,79,29,1,111,29,13,119,207,21,33,19,413,
%T A069608 49,71,183,223,153,21,261,369,29,319,107,1,273,81,711,507,87,579,401,
%U A069608 7,33,771,477,33,371,91,1559,357,297,9,177,523,77,103,167,199,143,199
%N A069608 a(1) = 6; a(n) = smallest number such that the juxtaposition a(1)a(2)...a(n) is a prime.
%H A069608 Michael S. Branicky, <a href="/A069608/b069608.txt">Table of n, a(n) for n = 1..303</a>
%e A069608 a(5) = 41 and the number 613141 is a prime.
%t A069608 a[1] = 6; 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}] (* _Robert G. Wilson v_, Aug 05 2005 *)
%o A069608 (Python)
%o A069608 from sympy import isprime
%o A069608 def aupton(terms):
%o A069608 alst, astr = [6], "6"
%o A069608 for n in range(2, terms+1):
%o A069608 an = 1
%o A069608 while not isprime(int(astr+str(an))): an += 1
%o A069608 alst, astr = alst + [an], astr + str(an)
%o A069608 return alst
%o A069608 print(aupton(62)) # _Michael S. Branicky_, Jun 01 2021
%Y A069608 Cf. A069602, A069604, A046256, A074342, A092528, A069603, A069605, A069606, A069607, A069608, A069609, A069610, A069611, A111525.
%K A069608 nonn,base
%O A069608 1,1
%A A069608 _Amarnath Murthy_, Mar 26 2002
%E A069608 More terms from _Jason Earls_, Jun 13 2002