Denominator of sum of -2nd powers of divisors of n.

Terms

a(0) =1a(1) =4a(2) =9a(3) =16a(4) =25a(5) =18a(6) =49a(7) =64a(8) =81a(9) =10a(10) =121a(11) =24a(12) =169a(13) =98a(14) =45a(15) =256a(16) =289a(17) =324a(18) =361a(19) =200a(20) =441a(21) =242a(22) =529a(23) =288a(24) =625a(25) =338a(26) =729a(27) =56a(28) =841a(29) =9