Column of Motzkin triangle.

Terms

a(0) =1a(1) =3a(2) =9a(3) =25a(4) =69a(5) =189a(6) =518a(7) =1422a(8) =3915a(9) =10813a(10) =29964a(11) =83304a(12) =232323a(13) =649845a(14) =1822824a(15) =5126520a(16) =14453451a(17) =40843521a(18) =115668105a(19) =328233969a(20) =933206967a(21) =2657946907a(22) =7583013474a(23) =21668135850a(24) =62007732605a(25) =177696228411a(26) =509899901553