OFFSET
1,1
COMMENTS
There are 598 such primes.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..598
EXAMPLE
7671737 is a prime and its first, third, fifth, and seventh digits are the same.
MATHEMATICA
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
CROSSREFS
KEYWORD
nonn,base,fini,full
AUTHOR
Harvey P. Dale, Feb 29 2016
STATUS
approved