a(1)=1; a(n+1) = Sum_{k=0..a(n) mod n} a(n-k).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =4a(5) =12a(6) =12a(7) =35a(8) =63a(9) =63a(10) =173a(11) =368a(12) =734a(13) =1448a(14) =2884a(15) =5607a(16) =11340a(17) =16947a(18) =39627a(19) =79301a(20) =118928a(21) =271750a(22) =543500a(23) =1092066a(24) =2184858a(25) =4358317a(26) =8727848a(27) =17455759a(28) =34911652a(29) =61095259