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A015979 Three iterations of Reverse and Add are needed to reach a palindrome.

%I A015979 #14 Aug 28 2024 10:58:52
%S A015979 59,68,77,86,95,155,156,157,158,164,165,168,178,180,184,185,186,194,
%T A015979 199,249,254,255,256,257,263,264,267,277,283,284,285,293,298,299,348,
%U A015979 349,353,354,355,356,362,363,366,376,382,383,384,389,392,397
%N A015979 Three iterations of Reverse and Add are needed to reach a palindrome.
%C A015979 The number of iterations starts at 1, so palindromes (cf. A002113) are not excluded. The corresponding sequence excluding palindromes is A065208.
%H A015979 Robert Israel, <a href="/A015979/b015979.txt">Table of n, a(n) for n = 1..10000</a>
%H A015979 <a href="/index/Res#RAA">Index entries for sequences related to Reverse and Add!</a>
%p A015979 filter:= proc(n,t) local x, d, m, L, i;
%p A015979   x:= n;
%p A015979   L:= convert(x,base,10);
%p A015979   for i from 1 to t do
%p A015979     d:= nops(L);
%p A015979     x:= add(L[i]*(10^(i-1) + 10^(d-i)),i=1..d);
%p A015979     L:= convert(x,base,10);
%p A015979     if L = ListTools:-Reverse(L) then return (i=t) fi;
%p A015979   od;
%p A015979   false
%p A015979 end proc:
%p A015979 select(filter, [$1..1000], 3); # _Robert Israel_, Aug 26 2024
%Y A015979 Cf. A002113, A065208.
%K A015979 nonn,base
%O A015979 1,1
%A A015979 _Robert G. Wilson v_
%E A015979 Offset corrected by _Robert Israel_, Aug 26 2024