T(2n+5,n), where T is the array in A055830.

Terms

a(0) =8a(1) =58a(2) =344a(3) =1918a(4) =10415a(5) =55837a(6) =297374a(7) =1578160a(8) =8359845a(9) =44244825a(10) =234094080a(11) =1238598580a(12) =6555004313a(13) =34703385031a(14) =183805639190a(15) =973982775784