a(1) = 2; a(n+1) = a(n)-th composite.

Terms

a(0) =2a(1) =6a(2) =12a(3) =21a(4) =33a(5) =49a(6) =69a(7) =94a(8) =125a(9) =164a(10) =212a(11) =270a(12) =339a(13) =422a(14) =520a(15) =636a(16) =774a(17) =933a(18) =1121a(19) =1339a(20) =1590a(21) =1880a(22) =2210a(23) =2587a(24) =3021a(25) =3512a(26) =4074a(27) =4710a(28) =5427a(29) =6239