a(n) = Pell(n)*A034896(n) for n >= 1, with a(0)=1, where A034896 lists the number of solutions to a^2 + b^2 + 3*c^2 + 3*d^2 = n.
A209451
a(n) = Pell(n)*A034896(n) for n >= 1, with a(0)=1, where A034896 lists the number of solutions to a^2 + b^2 + 3*c^2 + 3*d^2 = n.
Terms
- a(0) =1a(1) =4a(2) =8a(3) =20a(4) =240a(5) =696a(6) =280a(7) =5408a(8) =21216a(9) =3940a(10) =57072a(11) =275568a(12) =277200a(13) =1873816a(14) =2585024a(15) =4680600a(16) =54616512a(17) =81841608a(18) =10976840a(19) =530008720a(20) =1919331360a(21) =1235646880a(22) =4474673184a(23) =21605633376a(24) =28253665440a(25) =162655527004a(26) =177341693872a(27) =30581480180
External references
- oeis: A209451