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%I #11 Sep 01 2013 13:45:47
%S 10061,10091,10111,10141,10151,10181,10211,10271,10301,10321,10331,
%T 10391,10501,10531,10601,10631,10651,10691,10711,10771,10781,10831,
%U 10861,10891,11071,11131,11161,11171,11251,11261,11311,11321,11351,11411,11471,11491,11551
%N Primes of the form abcdabcd..abcda.
%C The sequence appears to be infinite. The number of terms below 10^1000 are 5749.
%H Shyam Sunder Gupta, <a href="/A187113/b187113.txt">Table of n, a(n) for n = 1..3032</a>
%e a(2)= 10091 is in the sequence because it is a prime of the form abcda.
%t s[n_]:=Select[Union@Flatten@Table[FromDigits@Flatten@Join[IntegerDigits@Table[b, {n}], {IntegerDigits@Floor[b/1000]}], {b, 1000, 9999}], PrimeQ]; Array[s, 2]//Flatten
%Y Cf. A228625, A228627
%K nonn,base
%O 1,1
%A _Shyam Sunder Gupta_, Aug 30 2013