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 A222236 #11 Mar 31 2017 00:19:40
%S A222236 0,1,2,6,4,5,3,7,8,9,10,11,12,16,14,15,13,17,18,19,20,21,22,26,24,25,
%T A222236 23,27,28,29,60,61,62,66,64,65,63,67,68,69,40,41,42,46,44,45,43,47,48,
%U A222236 49,50,51,52,56,54,55,53,57,58,59,30,31,32,36,34,35,33,37,38,39,70,71,72,76,74,75
%N A222236 In the number n, replace all (decimal) digits '3' with '6' and vice versa.
%C A222236 The map which is applied to primes in A171031.
%H A222236 Vincenzo Librandi, <a href="/A222236/b222236.txt">Table of n, a(n) for n = 0..1000</a>
%t A222236 a[n_]:= IntegerDigits[n]/.{3->6, 6->3} // FromDigits; Table[a[n], {n, 0, 80}] (* _Vincenzo Librandi_, Jul 30 2013 *)
%o A222236 (PARI) A222235(n,d=[0,1,2,6,4,5,3,7,8,9])={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 A222236 Cf. A222210-A222254; A171013-A171016, A175770, A171018-A171057.
%K A222236 nonn,base,easy
%O A222236 0,3
%A A222236 _M. F. Hasler_, Feb 12 2013