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 A171048 #11 Mar 31 2017 00:49:35
%S A171048 2,3,5,8,11,13,18,19,23,29,31,38,41,43,48,53,59,61,68,81,83,89,73,79,
%T A171048 98,101,103,108,109,113,128,131,138,139,149,151,158,163,168,183,189,
%U A171048 171,191,193,198,199,211,223,228,229,233,239,241,251,258,263
%N A171048 In the sequence of prime numbers, replace all the '8' digits with '7' and vice versa.
%H A171048 Vincenzo Librandi, <a href="/A171048/b171048.txt">Table of n, a(n) for n = 1..1000</a>
%t A171048 FromDigits[IntegerDigits[#]/.{8->p, 7->q}/.{p->7, q->8}]&/@Prime[Range[100]] (* _Vincenzo Librandi_, Mar 11 2013 *)
%o A171048 (PARI) a(n)=my(v=[0,1,2,3,4,5,6,8,7,9]);subst(Pol(apply(k->v[k+1], digits(prime(n)))),'x,10) \\ _Charles R Greathouse IV_, Jul 31 2013
%K A171048 nonn,base,easy
%O A171048 1,1
%A A171048 _N. J. A. Sloane_ and _Vincenzo Librandi_, Sep 04 2010