T(n,k) is the number of (n+2) X k 0..2 arrays with all rows having a nonnegative second derivative, and all columns having a positive second derivative in a quadratic least squares fit, with one and two element arrays taken as having a zero second derivative.
A223391
T(n,k) is the number of (n+2) X k 0..2 arrays with all rows having a nonnegative second derivative, and all columns having a positive second derivative in a quadratic least squares fit, with one and two element arrays taken as having a zero second derivative.
Terms
- a(0) =11a(1) =121a(2) =31a(3) =388a(4) =961a(5) =105a(6) =4794a(7) =5450a(8) =11025a(9) =342a(10) =40416a(11) =188958a(12) =120738a(13) =116964a(14) =1044a(15) =375698a(16) =4182458a(17) =14855514a(18) =2326103a(19) =1089936a(20) =3159a(21) =4128762a(22) =101698908a(23) =1030363654a(24) =993542957a(25) =40102656a(26) =9979281a(27) =9735a(28) =41424210a(29) =2972878486
External references
- oeis: A223391