Concatenation of composite numbers between the n-th prime and the following prime.

Terms

a(0) =4a(1) =6a(2) =8910a(3) =12a(4) =141516a(5) =18a(6) =202122a(7) =2425262728a(8) =30a(9) =3233343536a(10) =383940a(11) =42a(12) =444546a(13) =4849505152a(14) =5455565758a(15) =60a(16) =6263646566a(17) =686970a(18) =72a(19) =7475767778a(20) =808182a(21) =8485868788a(23) =9899100a(24) =102a(25) =104105106a(26) =108a(27) =110111112