Sum of proper divisors minus the number of proper divisors of Motzkin number A001006(n).

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =2a(5) =8a(6) =18a(7) =0a(8) =34a(9) =170a(10) =1643a(11) =3603a(12) =0a(13) =25118a(14) =139063a(15) =474559a(16) =284490a(17) =984006a(18) =6536387a(19) =24265729a(20) =18678366a(21) =96214018a(22) =277799290a(23) =1282283434a(24) =2077807072a(25) =1899874612a(26) =19252363859a(27) =44221482383a(28) =1967547352a(29) =29743945396