OFFSET
0,2
FORMULA
From Amiram Eldar, Sep 04 2022: (Start)
Sum_{n>=1} 1/a(n) = 13/2 - 7*Pi/sqrt(3) + 2*Pi^2/3.
Sum_{n>=1} (-1)^(n+1)/a(n) = 11/2 - 10*sqrt(5)*log(phi) + 24*log(phi)^2, where phi is the golden ratio (A001622). (End)
MAPLE
[seq ((2*n+n^2)*(binomial(2*n, n))/2, n=0..29)];
MATHEMATICA
Table[(2n+n^2)Binomial[2*n, n]/2, {n, 0, 25}] (* Harvey P. Dale, Feb 20 2011 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Zerinvary Lajos, May 31 2006
STATUS
approved