Number of Havender tableaux of height 2 with n columns.

A007345

Number of Havender tableaux of height 2 with n columns.

Terms

    a(0) =1a(1) =4a(2) =21a(3) =127a(4) =831a(5) =5722a(6) =40879a(7) =300440a(8) =2258455a(9) =17291704a(10) =134417955a(11) =1058279251a(12) =8422155293a(13) =67647554826a(14) =547699155261

External references