Number of subsets of {1..n} containing no sums or products of pairs of elements.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =6a(5) =11a(6) =17a(7) =30a(8) =45a(9) =71a(10) =101a(11) =171a(12) =258a(13) =427a(14) =606a(15) =988a(16) =1328a(17) =2141a(18) =3116a(19) =4952a(20) =6955a(21) =11031a(22) =15320a(23) =23978a(24) =33379a(25) =48698a(26) =66848a(27) =104852a(28) =144711a(29) =220757