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A068887 Primes with property that digits alternate in parity individually as well as in concatenation with previous terms. 1

%I #7 Dec 05 2013 19:55:14

%S 2,3,23,29,41,43,47,61,67,83,89,2129,2141,2143,2161,2309,2341,2347,

%T 2381,2383,2389,2503,2521,2543,2549,2707,2729,2741,2749,2767,2789,

%U 2903,2909,2927,2963,2969,4127,4129,4327,4349

%N Primes with property that digits alternate in parity individually as well as in concatenation with previous terms.

%t d[n_]:=IntegerDigits[n]; aQ[n_]:=Union[Abs[Differences[Boole@EvenQ[d[n]]]]]=={1}; t={2,3}; Do[p=Prime[i]; x=FromDigits[Flatten[{d[Last[t]],d[p]}]]; If[aQ[p] && aQ[x],AppendTo[t,p]],{i,5,600}]; t (* _Jayanta Basu_, May 23 2013 *)

%Y Cf. A030144.

%K base,nonn

%O 1,1

%A _Amarnath Murthy_, Mar 20 2002

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Last modified April 24 11:21 EDT 2024. Contains 371936 sequences. (Running on oeis4.)