Next-to-central column of triangle in A059317.

Terms

a(0) =0a(1) =0a(2) =1a(3) =2a(4) =8a(5) =22a(6) =72a(7) =218a(8) =691a(9) =2158a(10) =6833a(11) =21612a(12) =68726a(13) =218892a(14) =699197a(15) =2237450a(16) =7174018a(17) =23038582a(18) =74097134a(19) =238625222a(20) =769407486a(21) =2483532218a(22) =8024499657a(23) =25951580444a(24) =83999410292a(25) =272098963300a(26) =882045339733