a(n) = (a(n-1)*a(n-3) + 1) / a(n-4) with a(0) = a(1) = a(2) = a(3) = 1.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =3a(6) =4a(7) =9a(8) =14a(9) =19a(10) =43a(11) =67a(12) =91a(13) =206a(14) =321a(15) =436a(16) =987a(17) =1538a(18) =2089a(19) =4729a(20) =7369a(21) =10009a(22) =22658a(23) =35307a(24) =47956a(25) =108561a(26) =169166a(27) =229771a(28) =520147a(29) =810523