a(n) = Sum_{k=1..n} (-1)^(k+1) * floor(n/(2*k-1))^k.

Terms

a(0) =1a(1) =2a(2) =2a(3) =3a(4) =5a(5) =3a(6) =3a(7) =4a(8) =1a(9) =9a(10) =9a(11) =3a(12) =5a(13) =-9a(14) =1a(15) =2a(16) =4a(17) =25a(18) =25a(19) =63a(20) =-13a(21) =-75a(22) =-75a(23) =-89a(24) =-26a(25) =102a(26) =296a(27) =122a(28) =124a(29) =-58