a(n+1) = a(n) op n, where op is successively +, *, -.

Terms

a(0) =1a(1) =2a(2) =4a(3) =1a(4) =5a(5) =25a(6) =19a(7) =26a(8) =208a(9) =199a(10) =209a(11) =2299a(12) =2287a(13) =2300a(14) =32200a(15) =32185a(16) =32201a(17) =547417a(18) =547399a(19) =547418a(20) =10948360a(21) =10948339a(22) =10948361a(23) =251812303a(24) =251812279a(25) =251812304a(26) =6547119904a(27) =6547119877a(28) =6547119905a(29) =189866477245