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 A171049 #11 Mar 31 2017 00:48:45
%S A171049 2,3,5,7,11,13,17,10,23,20,31,37,41,43,47,53,50,61,67,71,73,70,83,80,
%T A171049 7,191,193,197,190,113,127,131,137,130,140,151,157,163,167,173,170,
%U A171049 181,101,103,107,100,211,223,227,220,233,230,241,251,257,263
%N A171049 In the sequence of prime numbers, replace all the '9' digits with '0' and vice versa.
%H A171049 Vincenzo Librandi, <a href="/A171049/b171049.txt">Table of n, a(n) for n = 1..1000</a>
%t A171049 FromDigits[IntegerDigits[#] /. {9 -> p, 0 -> q} /. {p -> 0, q -> 9}] & /@ Prime[Range[100]] (* _Vincenzo Librandi_, Apr 07 2013 *)
%o A171049 (PARI) a(n)=my(v=[9,1,2,3,4,5,6,7,8,0]);subst(Pol(apply(k->v[k+1], digits(prime(n)))),'x,10) \\ _Charles R Greathouse IV_, Jul 31 2013
%K A171049 nonn,base,easy
%O A171049 1,1
%A A171049 _N. J. A. Sloane_ and _Vincenzo Librandi_, Sep 04 2010