a(n) = Sum_{i=0..n} binomial(n,i)^2*i!*4^i.
A102773
a(n) = Sum_{i=0..n} binomial(n,i)^2*i!*4^i.
Terms
- a(0) =1a(1) =5a(2) =49a(3) =709a(4) =13505a(5) =318181a(6) =8916145a(7) =289283429a(8) =10656031489a(9) =439039941445
External references
- oeis: A102773