OFFSET
1,4
COMMENTS
a(n) >= 0.
REFERENCES
P. S. Bullen, A Dictionary of Inequalities, Longman, 1998. See p. 34.
D. S. Mitrinovic, Analytic Inequalities, Springer 1970. See (3.1.29).
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
Table[Binomial[2 n, n] - Ceiling[4^n / (2 Sqrt[n])], {n, 30}] (* Vincenzo Librandi, Feb 27 2017 *)
PROG
(Magma) [Binomial(2*n, n)-Ceiling(4^n/(2*Sqrt(n))): n in [1..30]]; // Vincenzo Librandi, Feb 27 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Feb 26 2017
STATUS
approved