a(1) = 1, a(2) = 2; a(n) = a(n-a(1)) + a(n-a(2)) + a(n-a(3)) + a(n-a(4)) + ...

Terms

a(0) =1a(1) =2a(2) =3a(3) =6a(4) =11a(5) =20a(6) =38a(7) =71a(8) =132a(9) =247a(10) =461a(11) =861a(12) =1609a(13) =3005a(14) =5613a(15) =10485a(16) =19584a(17) =36581a(18) =68330a(19) =127632a(20) =238404a(21) =445314a(22) =831798a(23) =1553712a(24) =2902170a(25) =5420945a(26) =10125754a(27) =18913838a(28) =35329048a(29) =65990929