Add 1, multiply by 1, add 2, multiply by 2, etc., start with 3.

Terms

a(0) =3a(1) =4a(2) =4a(3) =6a(4) =12a(5) =15a(6) =45a(7) =49a(8) =196a(9) =201a(10) =1005a(11) =1011a(12) =6066a(13) =6073a(14) =42511a(15) =42519a(16) =340152a(17) =340161a(18) =3061449a(19) =3061459a(20) =30614590a(21) =30614601a(22) =336760611a(23) =336760623a(24) =4041127476a(25) =4041127489a(26) =52534657357a(27) =52534657371a(28) =735485203194a(29) =735485203209