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A127691 a(n) = (2*n+1)^n-(2*n-1)^n-(2*n)^n. 2
-1, 0, 0, 2, 64, 2002, 69264, 2697354, 117899520, 5740530914, 308814720400, 18213955960378, 1169672907313728, 81286160430474066, 6080123714344570128, 487166244246501489002, 41636260100744439399424, 3781449867356996500139458, 363724112817207189865471248 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

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.

LINKS

Table of n, a(n) for n=0..18.

CROSSREFS

Sequence in context: A134939 A217268 A122603 * A013822 A010047 A187548

Adjacent sequences:  A127688 A127689 A127690 * A127692 A127693 A127694

KEYWORD

sign

AUTHOR

N. J. A. Sloane, Apr 03 2007

STATUS

approved

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Last modified June 13 12:44 EDT 2021. Contains 344996 sequences. (Running on oeis4.)