a(n) = a(n-7) + a(n-4) + a(n-1) for n>1 and a(n)=1 for n<=1.

Terms

a(0) =1a(1) =1a(2) =3a(3) =5a(4) =7a(5) =9a(6) =13a(7) =19a(8) =27a(9) =39a(10) =57a(11) =83a(12) =119a(13) =171a(14) =247a(15) =357a(16) =515a(17) =743a(18) =1073a(19) =1549a(20) =2235a(21) =3225a(22) =4655a(23) =6719a(24) =9697a(25) =13995a(26) =20199a(27) =29153a(28) =42075a(29) =60725