Erroneous version of A014284.

Terms

a(0) =1a(1) =2a(2) =6a(3) =11a(4) =18a(5) =29a(6) =42a(7) =59a(8) =78a(9) =101a(10) =130a(11) =161a(12) =198a(13) =239a(14) =282a(15) =329a(16) =382a(17) =441a(18) =502a(19) =569