Number of sum-free subsets of {1, ..., n}.

Terms

a(0) =1a(1) =2a(2) =3a(3) =6a(4) =9a(5) =16a(6) =24a(7) =42a(8) =61a(9) =108a(10) =151a(11) =253a(12) =369a(13) =607a(14) =847a(15) =1400a(16) =1954a(17) =3139a(18) =4398a(19) =6976a(20) =9583a(21) =15456a(22) =20982a(23) =32816a(24) =45417a(25) =70109a(26) =94499a(27) =148234a(28) =200768a(29) =308213