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 A222239 #10 Mar 31 2017 00:17:51
%S A222239 0,1,2,9,4,5,6,7,8,3,10,11,12,19,14,15,16,17,18,13,20,21,22,29,24,25,
%T A222239 26,27,28,23,90,91,92,99,94,95,96,97,98,93,40,41,42,49,44,45,46,47,48,
%U A222239 43,50,51,52,59,54,55,56,57,58,53,60,61,62,69,64,65,66,67,68,63,70,71,72,79,74,75
%N A222239 In the number n, replace all (decimal) digits '3' with '9' and vice versa.
%C A222239 The map which is applied to primes in A171052.
%H A222239 Vincenzo Librandi, <a href="/A222239/b222239.txt">Table of n, a(n) for n = 0..1000</a>
%t A222239 a[n_]:= IntegerDigits[n]/.{3->9, 9->3} // FromDigits; Table[a[n], {n, 0, 80}] (* _Vincenzo Librandi_, Jul 30 2013 *)
%o A222239 (PARI) A222239(n,d=[0, 1, 2, 9, 4, 5, 6, 7, 8, 3])=sum(i=1,#n=digits(n),d[n[i]+1]*10^(#n-i)) \\ gives correct result for n=0 iff d[1]=0, since digits(0)=[] in PARI (v.2.6)
%Y A222239 Cf. A222210-A222254; A171013-A171016, A175770, A171018-A171057.
%K A222239 nonn,base,easy
%O A222239 0,3
%A A222239 _M. F. Hasler_, Feb 13 2013