a(n) = a(n-1) + a(n-3) + a(n-5) - a(n-6), a(0) = a(1) = a(2) = 1, a(3) = 2, a(4) = 3, a(5) = 5.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =5a(6) =7a(7) =10a(8) =16a(9) =24a(10) =36a(11) =54a(12) =81a(13) =123a(14) =185a(15) =278a(16) =419a(17) =631a(18) =951a(19) =1432a(20) =2156a(21) =3248a(22) =4892a(23) =7368a(24) =11097a(25) =16713a(26) =25173a(27) =37914a(28) =57103a(29) =86005