a(n) = Sum_{k=1..n} floor(n/(2*k-1))^3.

Terms

a(0) =1a(1) =8a(2) =28a(3) =65a(4) =127a(5) =225a(6) =353a(7) =522a(8) =759a(9) =1037a(10) =1369a(11) =1803a(12) =2273a(13) =2827a(14) =3539a(15) =4260a(16) =5078a(17) =6095a(18) =7123a(19) =8301a(20) =9709a(21) =11103a(22) =12623a(23) =14449a(24) =16312a(25) =18270a(26) =20614a(27) =22920a(28) =25358a(29) =28338