|
%I #10 Sep 01 2013 13:46:07
%S 110311,110711,111211,111611,112111,113011,113111,114311,115211,
%T 115811,116411,116911,117511,117811,117911,118211,118411,119311,
%U 119611,130513,131113,131213,131413,131713,132113,132313,133013,133213,133813,134213,134513,135613
%N Primes of the form abcdabcd..abcdab.
%C The sequence appears to be infinite. The number of terms below 10^1000 are 5211.
%H Shyam Sunder Gupta, <a href="/A187114/b187114.txt">Table of n, a(n) for n = 1..2711</a>
%e a(2)= 110711 is in the sequence because it is a prime of the form abcdab.
%t s[n_]:=Select[Union@Flatten@Table[FromDigits@Flatten@Join[IntegerDigits@Table[b, {n}], {IntegerDigits@Floor[b/100]}], {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
|
