%I #5 Feb 27 2019 21:41:01
%S -1,0,0,2,64,2002,69264,2697354,117899520,5740530914,308814720400,
%T 18213955960378,1169672907313728,81286160430474066,
%U 6080123714344570128,487166244246501489002,41636260100744439399424,3781449867356996500139458,363724112817207189865471248
%N a(n) = (2*n+1)^n-(2*n-1)^n-(2*n)^n.
%C Theorem: (2*n+1)^n-(2*n-1)^n-(2*n)^n > 0 for n >= 3.
%D D. S. Mitrinovic, Analytic Inequalities, Springer-Verlag, 1970; p. 192, 3.1.13.
%K sign
%O 0,4
%A _N. J. A. Sloane_, Apr 03 2007