a(n) = ChebyshevT(4, n).

Terms

a(0) =1a(1) =1a(2) =97a(3) =577a(4) =1921a(5) =4801a(6) =10081a(7) =18817a(8) =32257a(9) =51841a(10) =79201a(11) =116161a(12) =164737a(13) =227137a(14) =305761a(15) =403201a(16) =522241a(17) =665857a(18) =837217a(19) =1039681a(20) =1276801a(21) =1552321a(22) =1870177a(23) =2234497a(24) =2649601a(25) =3120001a(26) =3650401a(27) =4245697a(28) =4910977a(29) =5651521