a(n) = Sum_{d|n} sigma(n*d).

Terms

a(0) =1a(1) =10a(2) =17a(3) =53a(4) =37a(5) =170a(6) =65a(7) =236a(8) =174a(9) =370a(10) =145a(11) =901a(12) =197a(13) =650a(14) =629a(15) =987a(16) =325a(17) =1740a(18) =401a(19) =1961a(20) =1105a(21) =1450a(22) =577a(23) =4012a(24) =968a(25) =1970a(26) =1618a(27) =3445a(28) =901a(29) =6290