a(n) = n^3 * Sum_{p|n, p prime} 1/p^3.

Terms

a(0) =0a(1) =1a(2) =1a(3) =8a(4) =1a(5) =35a(6) =1a(7) =64a(8) =27a(9) =133a(10) =1a(11) =280a(12) =1a(13) =351a(14) =152a(15) =512a(16) =1a(17) =945a(18) =1a(19) =1064a(20) =370a(21) =1339a(22) =1a(23) =2240a(24) =125a(25) =2205a(26) =729a(27) =2808a(28) =1a(29) =4591