Number of nonempty subsets of {1, 2, ..., n} with <=6 pairwise coprime elements.

Terms

a(0) =1a(1) =3a(2) =7a(3) =11a(4) =23a(5) =27a(6) =55a(7) =71a(8) =103a(9) =115a(10) =231a(11) =247a(12) =489a(13) =537a(14) =609a(15) =719a(16) =1383a(17) =1446a(18) =2674a(19) =2851a(20) =3204a(21) =3443a(22) =6110a(23) =6329a(24) =8484a(25) =9083a(26) =10930a(27) =11587a(28) =19252a(29) =19471