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

-1, 0, 0, 2, 64, 2002, 69264, 2697354, 117899520, 5740530914, 308814720400, 18213955960378, 1169672907313728, 81286160430474066, 6080123714344570128, 487166244246501489002, 41636260100744439399424, 3781449867356996500139458, 363724112817207189865471248

Offset: 0

Author

N. J. A. Sloane, Apr 03 2007

Keywords

• sign

Comments

Theorem: (2*n+1)^n-(2*n-1)^n-(2*n)^n > 0 for n >= 3.

References

• D. S. Mitrinovic, Analytic Inequalities, Springer-Verlag, 1970; p. 192, 3.1.13.