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 A171023 #10 Mar 31 2017 20:28:49
%S A171023 2,3,0,7,11,13,17,19,23,29,31,37,41,43,47,3,9,61,67,71,73,79,83,89,97,
%T A171023 151,153,157,159,113,127,131,137,139,149,101,107,163,167,173,179,181,
%U A171023 191,193,197,199,211,223,227,229,233,239,241,201,207,263,269
%N A171023 In the sequence of prime numbers, replace all the '5' digits with '0' and vice versa.
%H A171023 Vincenzo Librandi, <a href="/A171023/b171023.txt">Table of n, a(n) for n = 1..1000</a>
%t A171023 FromDigits[IntegerDigits[#]/.{5->p, 0->q}/.{p->0, q->5}]&/@Prime[Range[100]] (* _Vincenzo Librandi_, Apr 07 2013 *)
%o A171023 (PARI) a(n)=my(v=[5,1,2,3,4,0,6,7,8,9]);subst(Pol(apply(k->v[k+1], digits(prime(n)))),'x,10) \\ _Charles R Greathouse IV_, Jul 16 2013
%K A171023 nonn,base,easy
%O A171023 1,1
%A A171023 _N. J. A. Sloane_ and _Vincenzo Librandi_, Sep 04 2010