Number of c-squarefree numbers (A233564) less than 2^n.

Terms

a(0) =0a(1) =1a(2) =2a(3) =5a(4) =8a(5) =13a(6) =24a(7) =37a(8) =56a(9) =83a(10) =140a(11) =205a(12) =306a(13) =439a(14) =632a(15) =983a(16) =1418a(17) =2035a(18) =2886a(19) =4063a(20) =5618a(21) =8369a(22) =11666a(23) =16423a(24) =22716a(25) =31477a(26) =42782a(27) =58385a(28) =82700a(29) =113161