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 A127691 a(n) = (2*n+1)^n-(2*n-1)^n-(2*n)^n. 2

%I

%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

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Last modified November 28 05:56 EST 2022. Contains 358407 sequences. (Running on oeis4.)