T(n,k)=Number of nXk 0..2 arrays with all rows and columns having a nonnegative second derivative in a quadratic least squares fit, with one and two element arrays taken as having a zero second derivative.
A223195
T(n,k)=Number of nXk 0..2 arrays with all rows and columns having a nonnegative second derivative in a quadratic least squares fit, with one and two element arrays taken as having a zero second derivative.
Terms
- a(0) =3a(1) =9a(2) =9a(3) =16a(4) =81a(5) =16a(6) =50a(7) =256a(8) =256a(9) =50a(10) =138a(11) =2500a(12) =1138a(13) =2500a(14) =138a(15) =387a(16) =19044a(17) =20016a(18) =20016a(19) =19044a(20) =387a(21) =1143a(22) =149769a(23) =252544a(24) =1133664a(25) =252544a(26) =149769a(27) =1143a(28) =3402a(29) =1306449
External references
- oeis: A223195