a(n) = 2*a(n-1) - a(n-2) + (a(n-1)^2 + a(n-2)^2).
A122591
a(n) = 2*a(n-1) - a(n-2) + (a(n-1)^2 + a(n-2)^2).
Terms
- a(0) =1a(1) =1a(2) =3a(3) =15a(4) =261a(5) =68853a(6) =4740941175
External references
- oeis: A122591
A122591
a(n) = 2*a(n-1) - a(n-2) + (a(n-1)^2 + a(n-2)^2).