Number of subsets of {1,2,...,n} such that no two elements differ by 3 or 5.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =12a(5) =18a(6) =24a(7) =34a(8) =47a(9) =73a(10) =111a(11) =177a(12) =267a(13) =409a(14) =600a(15) =900a(16) =1324a(17) =2004a(18) =2996a(19) =4564a(20) =6848a(21) =10377a(22) =15513a(23) =23385a(24) =34953a(25) =52685a(26) =78969a(27) =119138a(28) =178840a(29) =269604