a(n) = Sum_{k=1..n-1} sigma_5(k)*sigma_5(n-k).

Terms

a(0) =0a(1) =1a(2) =66a(3) =1577a(4) =18218a(5) =135550a(6) =738236a(7) =3207785a(8) =11714718a(9) =37347144a(10) =106499470a(11) =277489886a(12) =668981686a(13) =1512360404a(14) =3228797252a(15) =6570019945a(16) =12793050456a(17) =24001960051a(18) =43483452090a(19) =76485144056a(20) =130752372320a(21) =218220937122a(22) =355664809556a(23) =568293832670a(24) =889969136158