Number of subsets of {1..n} containing no products of two or more distinct elements.

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =9a(5) =17a(6) =29a(7) =57a(8) =101a(9) =201a(10) =365a(11) =729a(12) =1233a(13) =2465a(14) =4593a(15) =8297a(16) =15921a(17) =31841a(18) =55953a(19) =111905a(20) =195713a(21) =362337a(22) =697361a(23) =1394721a(24) =2334113a(25) =4668225a(26) =9095393a(27) =17225313a(28) =31242785a(29) =62485569