cp's OEIS Frontend

A131207 Nonnegative integers n such that the difference between n and its reverse is a palindrome.

%I A131207 #23 Dec 01 2023 06:14:17
%S A131207 0,1,2,3,4,5,6,7,8,9,10,11,12,21,22,23,32,33,34,43,44,45,54,55,56,65,
%T A131207 66,67,76,77,78,87,88,89,98,99,100,101,102,110,111,112,120,121,122,
%U A131207 130,131,132,140,141,142,150,151,152,160,161,162,170,171,172,180
%N A131207 Nonnegative integers n such that the difference between n and its reverse is a palindrome.
%C A131207 a(n) = A178403(n) for n < 48. [_Reinhard Zumkeller_, May 27 2010]
%H A131207 David A. Corneth, <a href="/A131207/b131207.txt">Table of n, a(n) for n = 1..10000</a>
%e A131207 122 is in the sequence as the difference between 122 and its reversal (211) is 99 which is a palindrome. - _David A. Corneth_, Dec 01 2023
%p A131207 filter:= proc(n) local L,nL,r;
%p A131207   L:= convert(n,base,10);
%p A131207   nL:= nops(L);
%p A131207   r:= add(L[i]*10^(nL-i),i=1..nL);
%p A131207   L:= convert(abs(n-r),base,10);
%p A131207   evalb(L = ListTools:-Reverse(L))
%p A131207 end proc:
%p A131207 select(filter, [$0..1000]); # _Robert Israel_, Aug 26 2014
%t A131207 revpalQ[n_]:=Module[{diff=IntegerDigits[Abs[n-FromDigits[Reverse[ IntegerDigits[ n]]]]]},diff==Reverse[diff]]; Select[Range[ 0,400],revpalQ] (* _Harvey P. Dale_, Aug 22 2014 *)
%o A131207 (Java) for(i = 1; i <=1000; i++){ n = Math.abs(i - reverseNumber(i)); if(n == reverseNumber(n)){ System.out.println(i); } }
%o A131207 (PARI)
%o A131207 is(n) = {
%o A131207 	my(d = abs(fromdigits(Vecrev(digits(n))) - n));
%o A131207           d = digits(d);
%o A131207           d == Vecrev(d)
%o A131207 } \\ _David A. Corneth_, Dec 01 2023
%Y A131207 Cf. A002113, A178403.
%K A131207 nonn,base
%O A131207 1,3
%A A131207 Rachit Agrawal (rachit_agrawal(AT)daiict.ac.in), Oct 23 2007
%E A131207 Corrected by _Harvey P. Dale_, Aug 22 2014