Central terms of pendular trinomial triangle A122445.

Terms

a(0) =1a(1) =0a(2) =1a(3) =2a(4) =8a(5) =28a(6) =107a(7) =418a(8) =1676a(9) =6848a(10) =28418a(11) =119444a(12) =507440a(13) =2175500a(14) =9400207a(15) =40895602a(16) =178984212a(17) =787503168a(18) =3481278734a(19) =15454765948a(20) =68871993872a(21) =307981243608