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 A171035 #9 Mar 31 2017 11:10:39
%S A171035 2,3,5,1,77,73,71,79,23,29,37,31,47,43,41,53,59,67,61,17,13,19,83,89,
%T A171035 91,707,703,701,709,773,721,737,731,739,749,757,751,763,761,713,719,
%U A171035 787,797,793,791,799,277,223,221,229,233,239,247,257,251,263
%N A171035 In the sequence of prime numbers, replace all the '7' digits with '1' and vice versa.
%H A171035 Vincenzo Librandi, <a href="/A171035/b171035.txt">Table of n, a(n) for n = 1..1000</a>
%t A171035 FromDigits[IntegerDigits[#]/.{7->p, 1->q}/.{p->1, q->7}]&/@Prime[Range[100]] (* _Vincenzo Librandi_, Apr 07 2013 *)
%o A171035 (PARI) a(n)=my(v=[0,7,2,3,4,5,6,1,8,9]);subst(Pol(apply(k->v[k+1], digits(prime(n)))),'x,10) \\ _Charles R Greathouse IV_, Jul 25 2013
%K A171035 nonn,base,easy
%O A171035 1,1
%A A171035 _N. J. A. Sloane_ and _Vincenzo Librandi_, Sep 04 2010