Number of subsets of {1,2,...,n} such that no two elements differ by 3, 4, or 5.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =12a(5) =16a(6) =20a(7) =25a(8) =33a(9) =49a(10) =77a(11) =121a(12) =181a(13) =258a(14) =356a(15) =488a(16) =680a(17) =976a(18) =1432a(19) =2113a(20) =3089a(21) =4449a(22) =6329a(23) =8961a(24) =12729a(25) =18226a(26) =26292a(27) =38056a(28) =55012a(29) =79200