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Primes in which parity of digits alternates.
18

%I #11 Nov 21 2013 12:46:28

%S 2,3,5,7,23,29,41,43,47,61,67,83,89,101,103,107,109,127,149,163,167,

%T 181,307,347,349,367,383,389,503,509,521,523,541,547,563,569,587,701,

%U 709,727,743,761,769,787,907,929,941,947,967,983,2129,2141,2143,2161,2309

%N Primes in which parity of digits alternates.

%H Reinhard Zumkeller, <a href="/A030144/b030144.txt">Table of n, a(n) for n = 1..10000</a>

%F A010051(a(n)) * A228710(a(n)) = 1. - _Reinhard Zumkeller_, Aug 31 2013

%e 2129 is a term as 2, 1, 2 and 9 have even and odd parity alternately.

%t Join[{2,3,5,7},Select[Prime[Range[400]],Union[Abs[Differences[Boole/@ EvenQ[ IntegerDigits[#]]]]] == {1}&]] (* _Harvey P. Dale_, Jul 26 2011 *)

%o (Haskell)

%o a030144 n = a030144_list !! (n-1)

%o a030144_list = filter ((== 1) . a228710) a000040_list

%o -- _Reinhard Zumkeller_, Aug 31 2013

%Y Intersection of A000040 and A030141.

%Y Cf. A030143, A030152.

%K nonn,base

%O 1,1

%A _Patrick De Geest_

%E Offset corrected by _Reinhard Zumkeller_, Aug 31 2013