Concatenate "n" and "nextprime(n)".

Terms

a(0) =12a(1) =23a(2) =35a(3) =45a(4) =57a(5) =67a(6) =711a(7) =811a(8) =911a(9) =1011a(10) =1113a(11) =1213a(12) =1317a(13) =1417a(14) =1517a(15) =1617a(16) =1719a(17) =1819a(18) =1923a(19) =2023a(20) =2123a(21) =2223a(22) =2329a(23) =2429a(24) =2529a(25) =2629a(26) =2729a(27) =2829a(28) =2931a(29) =3031