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A029742 Nonpalindromic numbers.

%I A029742 #37 Jul 24 2024 15:34:00
%S A029742 10,12,13,14,15,16,17,18,19,20,21,23,24,25,26,27,28,29,30,31,32,34,35,
%T A029742 36,37,38,39,40,41,42,43,45,46,47,48,49,50,51,52,53,54,56,57,58,59,60,
%U A029742 61,62,63,64,65,67,68,69,70,71,72,73,74,75,76,78,79,80,81,82,83,84,85,86,87,89,90,91,92,93,94,95,96,97,98,100,102,103,104,105,106,107
%N A029742 Nonpalindromic numbers.
%C A029742 Complement of A002113; A136522(a(n)) = 0.
%C A029742 A064834(a(n)) > 0. - _Reinhard Zumkeller_, Sep 18 2013
%H A029742 Reinhard Zumkeller, <a href="/A029742/b029742.txt">Table of n, a(n) for n = 1..10000</a>
%H A029742 Patrick De Geest, <a href="http://www.worldofnumbers.com/index.html">World!Of Numbers</a>
%H A029742 <a href="/index/Pac#palindromes">Index entries for sequences related to palindromes</a>
%t A029742 palQ[n_]:=Module[{idn=IntegerDigits[n]},idn==Reverse[idn]]; DeleteCases[ Range[10,110],_?palQ] (* _Harvey P. Dale_, Jan 28 2012 *)
%t A029742 Table[If[PalindromeQ[n],Nothing,n],{n,120}] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jul 13 2019 *)
%o A029742 (Haskell)
%o A029742 a029742 n = a029742_list !! (n-1)
%o A029742 a029742_list = filter ((== 0) . a136522) [1..]
%o A029742 -- _Reinhard Zumkeller_, Oct 09 2011
%o A029742 (Magma) [n: n in [0..150] | Intseq(n) ne Reverse(Intseq(n))]; // _Bruno Berselli_, Apr 01 2015
%o A029742 (PARI) is(n)=my(d=digits(n)); d!=Vecrev(d) \\ _Charles R Greathouse IV_, Feb 06 2017
%o A029742 (Python)
%o A029742 def ok(n): s = str(n); return s != s[::-1]
%o A029742 print(list(filter(ok, range(108)))) # _Michael S. Branicky_, Oct 12 2021
%o A029742 (Python)
%o A029742 def A029742(n):
%o A029742     def f(x): return n+x//10**((l:=len(s:=str(x)))-(k:=l+1>>1))-(int(s[k-1::-1])>x%10**k)+10**(k-1+(l&1^1))-1
%o A029742     m, k = n, f(n)
%o A029742     while m != k:
%o A029742         m, k = k, f(k)
%o A029742     return m # _Chai Wah Wu_, Jul 24 2024
%Y A029742 Cf. A002113. Different from A031955.
%K A029742 nonn,base,easy,nice
%O A029742 1,1
%A A029742 _Patrick De Geest_
%E A029742 Offset corrected by _Reinhard Zumkeller_, Oct 09 2011