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 A222243 #11 Mar 31 2017 00:16:13
%S A222243 0,1,2,3,8,5,6,7,4,9,10,11,12,13,18,15,16,17,14,19,20,21,22,23,28,25,
%T A222243 26,27,24,29,30,31,32,33,38,35,36,37,34,39,80,81,82,83,88,85,86,87,84,
%U A222243 89,50,51,52,53,58,55,56,57,54,59,60,61,62,63,68,65,66,67,64,69,70,71,72,73,78,75
%N A222243 In the number n, replace all (decimal) digits '4' with '8' and vice versa.
%C A222243 The map which is applied to primes in A171045.
%H A222243 Vincenzo Librandi, <a href="/A222243/b222243.txt">Table of n, a(n) for n = 0..1000</a>
%t A222243 a[n_]:= IntegerDigits[n]/.{4->8, 8->4} // FromDigits; Table[a[n], {n, 0, 80}] (* _Vincenzo Librandi_, Jul 31 2013 *)
%o A222243 (PARI) A222243(n,d=[0, 1, 2, 3, 8, 5, 6, 7, 4, 9])={sum(i=1,#n=digits(n),d[n[i]+1]*10^(#n-i),!n*d[1])} \\ N.B.: digits(0)=[] in PARI (v.2.6)
%Y A222243 Cf. A222210-A222254; A171013-A171016, A175770, A171018-A171057.
%K A222243 nonn,base,easy
%O A222243 0,3
%A A222243 _M. F. Hasler_, Feb 13 2013