a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ... + a(n-3)*a(3) for n >= 4, with initial terms 1, 0, 2, 2.

Terms

a(0) =1a(1) =0a(2) =2a(3) =2a(4) =2a(5) =6a(6) =14a(7) =26a(8) =58a(9) =142a(10) =326a(11) =754a(12) =1826a(13) =4438a(14) =10750a(15) =26378a(16) =65354a(17) =162334a(18) =405046a(19) =1016546a(20) =2561074a(21) =6472550a(22) =16415086a(23) =41761786a(24) =106526810a(25) =272411054a(26) =698275622a(27) =1793763282a(28) =4617047618a(29) =11906277750