a(n) = Sum_{k=0..n} C(n,k)^2*(n-k)!*k^2.
A105219
a(n) = Sum_{k=0..n} C(n,k)^2*(n-k)!*k^2.
Terms
- a(0) =0a(1) =1a(2) =8a(3) =63a(4) =544a(5) =5225a(6) =55656a(7) =653023a(8) =8379008a(9) =116780049a(10) =1757211400a(11) =28394129951a(12) =490371506208
External references
- oeis: A105219