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%I #10 Mar 04 2016 06:57:11
%S 1010131,1011191,1012171,1014121,1014131,1014161,1015171,1016111,
%T 1017131,1110181,1111151,1111181,1112131,1112141,1112171,1113181,
%U 1114111,1115131,1117111,1118101,1119121,1210151,1211141,1211191,1212121,1212191,1213141,1213151
%N Seven-digit primes whose first, third, fifth, and seventh digits are the same.
%C There are 598 such primes.
%H Harvey P. Dale, <a href="/A269564/b269564.txt">Table of n, a(n) for n = 1..598</a>
%e 7671737 is a prime and its first, third, fifth, and seventh digits are the same.
%t Table[Select[Prime[Range[PrimePi[i*10^6]+1,PrimePi[i*10^6+ 10^6-1]]], MatchQ[ IntegerDigits[#],{x_,_,x_,_,x_,_,x_}]&],{i,{1,3,7,9}}] //Flatten
%Y Cf. A269066.
%K nonn,base,fini,full
%O 1,1
%A _Harvey P. Dale_, Feb 29 2016
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