Number of lattice paths from (0,0) to (n,n) which do not go above the diagonal x=y using steps (1,k), (k,1) with k>=2.

A263316

Number of lattice paths from (0,0) to (n,n) which do not go above the diagonal x=y using steps (1,k), (k,1) with k>=2.

Terms

    a(0) =1a(1) =0a(2) =0a(3) =1a(4) =1a(5) =3a(6) =7a(7) =16a(8) =40a(9) =98a(10) =246a(11) =624a(12) =1596a(13) =4120a(14) =10708a(15) =28009a(16) =73673a(17) =194743a(18) =517067a(19) =1378365a(20) =3687665a(21) =9898417a(22) =26649117a(23) =71943947a(24) =194717215a(25) =528236599a(26) =1436122339a(27) =3912244667a(28) =10677558423a(29) =29192753795

External references