Number of nX2 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.
A223221
Number of nX2 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) =4a(1) =16a(2) =25a(3) =121a(4) =361a(5) =1369a(6) =4624a(7) =18769a(8) =68121a(9) =299209a(10) =1096209a(11) =4347225a(12) =17288964a(13) =71961289a(14) =271129156a(15) =1103036944a(16) =4381513249a(17) =17397082404a(18) =69668546704a(19) =278284735729
External references
- oeis: A223221