The first of three triangles counting 3-colored alternating permutations by their last value.

Terms

a(0) =1a(1) =0a(2) =1a(3) =9a(4) =9a(5) =8a(6) =0a(7) =9a(8) =18a(9) =26a(10) =405a(11) =405a(12) =396a(13) =378a(14) =352a(15) =0a(16) =405a(17) =810a(18) =1206a(19) =1584a(20) =1936a(21) =44469a(22) =44469a(23) =44064a(24) =43254a(25) =42048a(26) =40464a(27) =38528a(28) =0a(29) =44469