Dirichlet convolution of [ 1,1,1,... ] with Ramanujan numbers (A000594).

Terms

a(0) =1a(1) =-23a(2) =253a(3) =-1495a(4) =4831a(5) =-5819a(6) =-16743a(7) =82985a(8) =-113390a(9) =-111113a(10) =534613a(11) =-378235a(12) =-577737a(13) =385089a(14) =1222243a(15) =1070121a(16) =-6905933a(17) =2607970a(18) =10661421a(19) =-7222345a(20) =-4235979a(21) =-12296099a(22) =18643273a(23) =20995205a(24) =-25494394a(25) =13287951