Number of (1,0)-steps of weight 1 at level 0 in all weighted lattice paths in L_n.

Terms

a(0) =0a(1) =1a(2) =2a(3) =5a(4) =14a(5) =36a(6) =94a(7) =247a(8) =646a(9) =1691a(10) =4428a(11) =11592a(12) =30348a(13) =79453a(14) =208010a(15) =544577a(16) =1425722a(17) =3732588a(18) =9772042a(19) =25583539a(20) =66978574a(21) =175352183a(22) =459077976a(23) =1201881744a(24) =3146567256a(25) =8237820025a(26) =21566892818a(27) =56462858429a(28) =147821682470a(29) =387002188980