a(n) = Sum_{j=1..n} Sum_{k=1..n} sigma(j*k).

Terms

a(0) =1a(1) =14a(2) =59a(3) =190a(4) =401a(5) =914a(6) =1499a(7) =2632a(8) =4113a(9) =6424a(10) =8645a(11) =13284a(12) =17023a(13) =23092a(14) =30715a(15) =40484a(16) =48711a(17) =63890a(18) =75351a(19) =95792a(20) =116421a(21) =139822a(22) =159911a(23) =199176a(24) =229499a(25) =267438a(26) =309283a(27) =364462a(28) =404933a(29) =482792