a(n) = 2^(4*n-3)*n*(2*n-1)*(900*n^4-4500*n^3+8895*n^2-8055*n+2764), a closed form for a double binomial sum involving absolute values.
A269877
a(n) = 2^(4*n-3)*n*(2*n-1)*(900*n^4-4500*n^3+8895*n^2-8055*n+2764), a closed form for a double binomial sum involving absolute values.
Terms
- a(0) =0a(1) =8a(2) =121728a(3) =77214720a(4) =12676235264
External references
- oeis: A269877