Primes which are the concatenation of primes p and 2*p-1.

Terms

a(0) =23a(1) =367733a(2) =6611321a(3) =6911381a(4) =9971993a(5) =14592917a(6) =20114021a(7) =25575113a(8) =27075413a(9) =30616121a(10) =39677933a(11) =40278053a(12) =41778353a(13) =43578713a(14) =46399277a(15) =574911497a(16) =621112421a(17) =622912457a(18) =696113921a(19) =753715073a(20) =756115121a(21) =795115901a(22) =819116381a(23) =862917257a(24) =868917377a(25) =961919237a(26) =1078921577a(27) =1083721673a(28) =1131122621