a(n) = Sum_{i+j+k+m=n, i,j,k,m >= 1} tau(i) * tau(j) * tau(k) * tau(m).

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =8a(5) =32a(6) =92a(7) =216a(8) =440a(9) =814a(10) =1392a(11) =2244a(12) =3452a(13) =5096a(14) =7292a(15) =10129a(16) =13760a(17) =18284a(18) =23868a(19) =30662a(20) =38820a(21) =48556a(22) =59948a(23) =73424a(24) =88796a(25) =106886a(26) =127052a(27) =150732a(28) =176560a(29) =206920