a(n) = [ a(n-1)/a(1) ] + [ a(n-3)/a(3) ] + [ a(n-5)/a(5) ] + ..., for n >= 3.

Terms

a(0) =1a(1) =2a(2) =2a(3) =2a(4) =3a(5) =4a(6) =5a(7) =6a(8) =8a(9) =11a(10) =15a(11) =20a(12) =27a(13) =37a(14) =51a(15) =70a(16) =96a(17) =134a(18) =186a(19) =257a(20) =356a(21) =495a(22) =686a(23) =952a(24) =1320a(25) =1834a(26) =2547a(27) =3536a(28) =4911a(29) =6821