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 A222229 #14 Jun 13 2025 07:39:37
%S A222229 0,1,5,3,4,2,6,7,8,9,10,11,15,13,14,12,16,17,18,19,50,51,55,53,54,52,
%T A222229 56,57,58,59,30,31,35,33,34,32,36,37,38,39,40,41,45,43,44,42,46,47,48,
%U A222229 49,20,21,25,23,24,22,26,27,28,29,60,61,65,63,64,62,66,67
%N A222229 In the number n, replace all (decimal) digits '2' with '5' and vice versa.
%C A222229 The map which is applied to primes in A171025.
%H A222229 Vincenzo Librandi, <a href="/A222229/b222229.txt">Table of n, a(n) for n = 0..1000</a>
%t A222229 a[n_]:= IntegerDigits[n]/.{2->5, 5->2} // FromDigits; Table[a[n], {n, 0, 80}] (* _Vincenzo Librandi_, Jul 30 2013 *)
%o A222229 (PARI) A222229(n,d=[0,1,5,3,4,2,6,7,8,9])=sum(i=1, #n=digits(n), d[n[i]+1]*10^(#n-i)) \\ gives correct value for n=0 iff d[1]=0, since digits(0)=[] in PARI (v.2.6)
%Y A222229 Cf. A222210-A222254; A171013-A171016, A175770, A171018-A171057.
%K A222229 nonn,base,easy
%O A222229 0,3
%A A222229 _M. F. Hasler_, Feb 12 2013