a(1)=4. a(n) = a(n-1) + n, if a(n-1)+n is composite. Otherwise a(n) = a(n-1)*n.

Terms

a(0) =4a(1) =6a(2) =9a(3) =36a(4) =180a(5) =186a(6) =1302a(7) =1310a(8) =11790a(9) =11800a(10) =11811a(11) =11823a(12) =11836a(13) =11850a(14) =11865a(15) =11881a(16) =11898a(17) =11916a(18) =11935a(19) =11955a(20) =11976a(21) =11998a(22) =12021a(23) =12045a(24) =12070a(25) =12096a(26) =12123a(27) =12151a(28) =12180a(29) =12210