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Odd palindromes in which parity of digits alternates.
3

%I #8 May 15 2021 17:50:36

%S 1,3,5,7,9,101,121,141,161,181,303,323,343,363,383,505,525,545,565,

%T 585,707,727,747,767,787,909,929,949,969,989,10101,10301,10501,10701,

%U 10901,12121,12321,12521,12721,12921,14141,14341,14541,14741

%N Odd palindromes in which parity of digits alternates.

%H Matthew House, <a href="/A030148/b030148.txt">Table of n, a(n) for n = 1..10000</a>

%t apQ[n_]:=And@@(#[[1]]!=#[[2]]&/@Partition[Boole[EvenQ[ IntegerDigits[ n]]],2,1]); Select[Range[1,15000,2],PalindromeQ[#]&&apQ[#]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, May 15 2021 *)

%K nonn,base

%O 1,2

%A _Patrick De Geest_