Dana Scott's sequence: a(n) = (a(n-2) + a(n-1) * a(n-3)) / a(n-4), a(0) = a(1) = a(2) = a(3) = 1.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =3a(6) =5a(7) =13a(8) =22a(9) =41a(10) =111a(11) =191a(12) =361a(13) =982a(14) =1693a(15) =3205a(16) =8723a(17) =15042a(18) =28481a(19) =77521a(20) =133681a(21) =253121a(22) =688962a(23) =1188083a(24) =2249605a(25) =6123133a(26) =10559062a(27) =19993321a(28) =54419231a(29) =93843471