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A030150 Palindromic primes in which parity of digits alternates. 2

%I #9 Jul 10 2023 10:57:57

%S 2,3,5,7,101,181,383,727,787,929,10301,10501,12721,14341,14741,16361,

%T 16561,18181,30103,30703,32323,34543,36563,38183,38783,70507,72727,

%U 74747,76367,78787,90709,94349,94949,96769,98389,1074701

%N Palindromic primes in which parity of digits alternates.

%H Giovanni Resta, <a href="/A030150/b030150.txt">Table of n, a(n) for n = 1..10000</a>

%t altQ[n_] := n < 10 || Union[Total /@ Partition[ Mod[ IntegerDigits@ n, 2], 2, 1]] == {1}; palQ[n_] := Block[{d = IntegerDigits[n]}, d == Reverse@ d]; Select[ Prime@ Range@ 10000, palQ[#] && altQ[#] &] (* _Giovanni Resta_, Aug 16 2018 *)

%t Join[{2,3,5,7},Select[Prime[Range[85000]],PalindromeQ[#]&&Union[Total/@Partition[ Boole[ EvenQ/@IntegerDigits[#]],2,1]]=={1}&]] (* _Harvey P. Dale_, Jul 10 2023 *)

%Y Cf. A030144, A030147, A030148, A030149.

%K nonn,base

%O 1,1

%A _Patrick De Geest_

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Last modified March 28 14:20 EDT 2024. Contains 371254 sequences. (Running on oeis4.)