a(n) = Sum_{k=0..n} binomial(n,k) * ( binomial(n,k) - binomial(n,k-1) )^2.

A381676

a(n) = Sum_{k=0..n} binomial(n,k) * ( binomial(n,k) - binomial(n,k-1) )^2.

Terms

    a(0) =1a(1) =1a(2) =4a(3) =17a(4) =86a(5) =472a(6) =2752a(7) =16753a(8) =105394a(9) =680366a(10) =4484360a(11) =30067160a(12) =204508240a(13) =1408057120a(14) =9796738304a(15) =68786005361a(16) =486845236106

External references