P_4(2n+1), the Legendre polynomial of order 4 at 2n+1.

Terms

a(0) =1a(1) =321a(2) =2641a(3) =10321a(4) =28401a(5) =63601a(6) =124321a(7) =220641a(8) =364321a(9) =568801a(10) =849201a(11) =1222321a(12) =1706641a(13) =2322321a(14) =3091201a(15) =4036801a(16) =5184321a(17) =6560641a(18) =8194321a(19) =10115601a(20) =12356401a(21) =14950321a(22) =17932641a(23) =21340321a(24) =25212001a(25) =29588001