Second-order Eulerian numbers <<n,3>>.

Terms

a(0) =0a(1) =24a(2) =444a(3) =4400a(4) =32120a(5) =195800a(6) =1062500a(7) =5326160a(8) =25243904a(9) =114876376a(10) =507259276a(11) =2189829808a(12) =9292526920a(13) =38917528600a(14) =161343812980a(15) =663661077072