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

A223157

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

Terms

    a(0) =99a(1) =989a(2) =989a(3) =16089a(4) =25929a(5) =16089a(6) =215563a(7) =1328305a(8) =1328305a(9) =215563a(10) =2616383a(11) =55977857a(12) =261298801a(13) =55977857a(14) =2616383a(15) =31465359a(16) =1853983303a(17) =40346506449a(18) =40346506449a(19) =1853983303a(20) =31465359a(21) =363006521a(22) =63763662879

External references