Number of valleys in all weighted lattice paths in B(n).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =1a(7) =4a(8) =14a(9) =45a(10) =135a(11) =391a(12) =1105a(13) =3067a(14) =8404a(15) =22806a(16) =61428a(17) =164495a(18) =438459a(19) =1164363a(20) =3082717a(21) =8141422a(22) =21457255a(23) =56455195a(24) =148323305a(25) =389213825a(26) =1020283146a(27) =2672225692a(28) =6993600748a(29) =18291536552