a(n) = Pell(n)*A000118(n) for n>=1 with a(0)=1, where A000118(n) is the number of ways of writing n as a sum of 4 squares.

A209443

a(n) = Pell(n)*A000118(n) for n>=1 with a(0)=1, where A000118(n) is the number of ways of writing n as a sum of 4 squares.

Terms

    a(0) =1a(1) =8a(2) =48a(3) =160a(4) =288a(5) =1392a(6) =6720a(7) =10816a(8) =9792a(9) =102440a(10) =342432a(11) =551136a(12) =1330560a(13) =3747632a(14) =15510144a(15) =37444800a(16) =11299968a(17) =163683216a(18) =856193520a(19) =1060017440a(20) =2303197632a(21) =9885175040a(22) =26848039104a(23) =43211266752a(24) =52160613120a(25) =325311054008

External references