Sum of the heights of all left factors of Dyck paths of length n.

Terms

a(0) =1a(1) =3a(2) =6a(3) =14a(4) =28a(5) =61a(6) =121a(7) =257a(8) =508a(9) =1065a(10) =2103a(11) =4372a(12) =8634a(13) =17842a(14) =35254a(15) =72524a(16) =143396a(17) =293968a(18) =581630a(19) =1189102a(20) =2354168a(21) =4802331a(22) =9512984a(23) =19370764a(24) =38391332a(25) =78056544a(26) =154773135a(27) =314281350a(28) =623427154a(29) =1264546021