Next term is uniquely the sum of 3 earlier terms.

Terms

a(0) =1a(1) =2a(2) =4a(3) =7a(4) =10a(5) =12a(6) =16a(7) =17a(8) =32a(9) =36a(10) =42a(11) =57a(12) =72a(13) =73a(14) =98a(15) =102a(16) =104a(17) =129a(18) =159a(19) =164a(20) =174a(21) =189a(22) =199a(23) =221a(24) =224a(25) =255a(26) =286a(27) =287a(28) =347a(29) =372