T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with all rows and columns having a strictly positive second derivative in a quadratic least squares fit.

A223159

T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with all rows and columns having a strictly positive second derivative in a quadratic least squares fit.

Terms

    a(0) =2218a(1) =55790a(2) =55790a(3) =2077712a(4) =5026270a(5) =2077712a(6) =68181369a(7) =765677906a(8) =765677906a(9) =68181369a(10) =1978616080a(11) =102504263355a(12) =566068245194a(13) =102504263355a(14) =1978616080a(15) =57277247088

External references