Number of subsets of {1..n} containing all of their pairwise sums <= n.

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =7a(5) =12a(6) =16a(7) =27a(8) =37a(9) =58a(10) =80a(11) =131a(12) =171a(13) =277a(14) =380a(15) =580a(16) =785a(17) =1250a(18) =1655a(19) =2616a(20) =3516a(21) =5344a(22) =7257a(23) =11353a(24) =14931a(25) =23204a(26) =31379a(27) =47511a(28) =63778a(29) =98681