Skew circulant quadratic forms

Dennis Garbanati, Robert C. Thompson
1972 Journal of Number Theory  
This paper investigates positive definite unimodular quadratic forms in n variables with rational integer coefficients and a skew circulant as the coefficient matrix. It is shown for n < 13 that every such form is in the principal class, but that this no longer holds for n = 14. It is also shown that such forms can never be even. This behaviour is opposite to that for forms with a circulant as the coefficient matrix.
doi:10.1016/0022-314x(72)90028-5 fatcat:mj6ft7hccncujnkuhrmecka4me