Number of paths from (0,0) to (n,n) that always move closer to (n,n) (and do not pass (n,n) and backtrack).

A052141

Number of paths from (0,0) to (n,n) that always move closer to (n,n) (and do not pass (n,n) and backtrack).

Terms

    a(0) =1a(1) =3a(2) =26a(3) =252a(4) =2568a(5) =26928a(6) =287648a(7) =3112896a(8) =34013312a(9) =374416128a(10) =4145895936a(11) =46127840256a(12) =515268544512

External references