Chocolate dove bar numerator: a(n) = (Sum_{k=0..floor(n/2)} k*binomial(n+k,k)*binomial(n,n-2*k)) + (Sum_{k=0..ceiling(n/2)} k*binomial(n+k-1,k-1)*binomial(n,n-2*k+1)).

A167660

Chocolate dove bar numerator: a(n) = (Sum_{k=0..floor(n/2)} k*binomial(n+k,k)*binomial(n,n-2*k)) + (Sum_{k=0..ceiling(n/2)} k*binomial(n+k-1,k-1)*binomial(n,n-2*k+1)).

Terms

    a(0) =0a(1) =1a(2) =5a(3) =23a(4) =104a(5) =458a(6) =1987a(7) =8523a(8) =36248a(9) =153134a(10) =643466a(11) =2691926a(12) =11220156a(13) =46620412a(14) =193190831a(15) =798700531a(16) =3295291440a(17) =13571239766a(18) =55801698214a(19) =229113328722a(20) =939486081152

External references