a(n) = T(n,n+2), where T = Delannoy triangle (A008288).

A026002

a(n) = T(n,n+2), where T = Delannoy triangle (A008288).

Terms

    a(0) =1a(1) =7a(2) =41a(3) =231a(4) =1289a(5) =7183a(6) =40081a(7) =224143a(8) =1256465a(9) =7059735a(10) =39753273a(11) =224298231a(12) =1267854873a(13) =7178461215a(14) =40704778785a(15) =231128079903

External references