Number of nX3 0..1 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.

A223222

Number of nX3 0..1 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) =5a(1) =25a(2) =48a(3) =280a(4) =1036a(5) =4656a(6) =21300a(7) =99324a(8) =447912a(9) =2331228a(10) =11037718a(11) =54004060a(12) =266072957a(13) =1384937047a(14) =6366715673a(15) =32524690652a(16) =162457235830a(17) =799368028605

External references