cp's OEIS Frontend

A068637 a(n) = Max(n, R(n)), where R(n) (A004086) = digit reversal of n.

%I A068637 #14 Jun 26 2025 16:27:04
%S A068637 1,2,3,4,5,6,7,8,9,10,11,21,31,41,51,61,71,81,91,20,21,22,32,42,52,62,
%T A068637 72,82,92,30,31,32,33,43,53,63,73,83,93,40,41,42,43,44,54,64,74,84,94,
%U A068637 50,51,52,53,54,55,65,75,85,95,60,61,62,63,64,65,66,76,86,96,70,71
%N A068637 a(n) = Max(n, R(n)), where R(n) (A004086) = digit reversal of n.
%C A068637 a(n) = A004186(n) for n <= 100. - _Reinhard Zumkeller_, Apr 03 2015
%H A068637 Reinhard Zumkeller, <a href="/A068637/b068637.txt">Table of n, a(n) for n = 1..10000</a>
%e A068637 a(12) = max(12,21) = 21. a(34632) = max(34632,23643) = 34632.
%p A068637 a:= n-> max(n,(s-> parse(cat(seq(s[-i], i=1..length(s)))))(""||n)):
%p A068637 seq(a(n), n=1..100);  # _Alois P. Heinz_, Aug 22 2015
%t A068637 Table[Max[n,IntegerReverse[n]],{n,100}] (* The program uses the IntegerReverse function from Mathematica version 10 *) (* _Harvey P. Dale_, Jan 10 2016 *)
%o A068637 (Haskell)
%o A068637 a068637 n = max n $ a004086 n  -- _Reinhard Zumkeller_, Apr 03 2015
%o A068637 (Python)
%o A068637 def A068637(n): return max(n,int(str(n)[::-1])) # _Chai Wah Wu_, Jun 26 2025
%Y A068637 Cf. A068636.
%Y A068637 Cf. A004086, A004186.
%K A068637 base,easy,nonn,hear,look
%O A068637 1,2
%A A068637 _Amarnath Murthy_, Feb 27 2002
%E A068637 Wrong a(13)=22 removed by _Reinhard Zumkeller_, Apr 03 2015