Enumeration of bent functions on the minimal distance from the quadratic bent function

Constructing bent functions on the minimal distance from the quadratic bent function is studied. All such bent functions in $2k$ variables are obtained and it is shown that the number of them is equal to $2^k(2^1+1)\dots(2^k+1)$. A lower bound of the number of bent functions on the minimal distance from a Maiorana–McFarland bent function is given. Tab. 1, bibliogr. 9.