%I #19 May 17 2019 06:04:36

%S 1,1,6,5040,1307674368000,8222838654177922817725562880000000,

%T 1982608315404440064116146708361898137544773690227268628106279599612729753600000000000000

%N a(n) = (2^n - 1)!.

%H I. Strazdins, <a href="https://doi.org/10.1023/A:1005769927571">Universal affine classification of Boolean functions</a>, Acta Applic. Math. 46 (1997), 147-167.

%t (2^Range[0, 6] - 1)! (* _Alonso del Arte_, Dec 24 2016 *)

%o (PARI) for(n=0, 10, print1((2^n -1)!, ", ")) \\ _G. C. Greubel_, Dec 25 2016

%Y Cf. A000142, A000225.

%K nonn,easy

%O 0,3

%A _N. J. A. Sloane_