Number of 5-element nondividing subsets of {1, 2, ..., n}.

Terms

a(0) =2a(1) =4a(2) =6a(3) =11a(4) =15a(5) =24a(6) =50a(7) =83a(8) =127a(9) =209a(10) =310a(11) =431a(12) =679a(13) =921a(14) =1229a(15) =1624a(16) =2145a(17) =2770a(18) =3752a(19) =4866a(20) =6141a(21) =7753a(22) =9679a(23) =12005a(24) =15027a(25) =18134a(26) =22045a(27) =26368a(28) =31712a(29) =37763