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

Terms

a(0) =0a(1) =0a(2) =1a(3) =3a(4) =4a(5) =11a(6) =21a(7) =1a(8) =37a(9) =173a(10) =1648a(11) =3610a(12) =1a(13) =25125a(14) =139086a(15) =474576a(16) =284493a(17) =984021a(18) =6536394a(19) =24265740a(20) =18678381a(21) =96214041a(22) =277799337a(23) =1282283505a(24) =2077807083a(25) =1899874619a(26) =19252363864a(27) =44221482398a(28) =1967547359a(29) =29743945411