Juxtapose pairs of primes.

Terms

a(0) =23a(1) =57a(2) =1113a(3) =1719a(4) =2329a(5) =3137a(6) =4143a(7) =4753a(8) =5961a(9) =6771a(10) =7379a(11) =8389a(12) =97101a(13) =103107a(14) =109113a(15) =127131a(16) =137139a(17) =149151a(18) =157163a(19) =167173a(20) =179181a(21) =191193a(22) =197199a(23) =211223a(24) =227229a(25) =233239a(26) =241251a(27) =257263a(28) =269271a(29) =277281