Dirichlet convolution of Ramanujan numbers (A000594) with themselves.

Terms

a(0) =1a(1) =-48a(2) =504a(3) =-2368a(4) =9660a(5) =-24192a(6) =-33488a(7) =239616a(8) =-163782a(9) =-463680a(10) =1069224a(11) =-1193472a(12) =-1155476a(13) =1607424a(14) =4868640a(15) =86016a(16) =-13811868a(17) =7861536a(18) =21322840a(19) =-22874880a(20) =-16877952a(21) =-51322752a(22) =37286544a(23) =120766464a(24) =-27669550a(25) =55462848a(26) =-203834232