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%I #12 Feb 25 2021 08:30:22
%S 1,2,3,5,6,7,11,22,33,55,66,77,101,111,131,141,151,161,181,191,202,
%T 222,262,282,303,313,323,353,373,383,393,434,454,474,494,505,515,535,
%U 545,555,565,595,606,626,646,707,717,727,737,757,767,777,787,797,818,838
%N Squarefree palindromes.
%H Amiram Eldar, <a href="/A071251/b071251.txt">Table of n, a(n) for n = 1..10000</a>
%p ffpal := proc(n) local i,j,k,s,aa,nn,bb,flag; s := n; aa := convert(s,string); nn := length(aa); bb := ``; for i from nn by -1 to 1 do bb := cat(bb,substring(aa,i..i)); od; flag := 0; for j from 1 to nn do if substring(aa,j..j)<>substring(bb,j..j) then flag := 1 fi; od; RETURN(flag); end: ts_ndk_pal := proc(i) if ffpal((i)) = 0 then if (numtheory[issqrfree](i) = 'true' ) then RETURN((i)) fi fi end: andkpal := [seq(ts_ndk_pal(i), i=1..10000)]: andkpal;
%t Select[ Range[ 1000], # == FromDigits[ Reverse[ IntegerDigits[ # ]]] && Max[ Transpose[ FactorInteger[ # ]] [[2]]] < 2 &]
%t Select[Range[1000],PalindromeQ[#]&&SquareFreeQ[#]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Dec 17 2018 *)
%Y Intersection of A002113 and A005117.
%Y Cf. A002385, A069217, A032350, A035132.
%K base,nonn
%O 1,2
%A _Amarnath Murthy_, May 21 2002
%E Edited by _Robert G. Wilson v_, Jun 03 2002
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