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A085568
Numerator of 2*Sum(C(n,w)/(2*w+1),w=0..n/2-1)+C(n,n/2)/(n+1) if n is even, or of 2*Sum(C(n,w)/(2*w+1),w=0..(n-1)/2) if n is odd.
5
1, 2, 8, 4, 88, 28, 104, 376, 1904, 372, 30152, 4952, 193072, 245848, 64304, 7984, 8303392, 32131172, 126932136, 164384184, 185914544, 16850280, 3006076208, 249890288, 5554299808, 21745428728, 9598969456, 37645191344, 5687521456416, 378608431568, 4518712438048
OFFSET
0,2
EXAMPLE
1, 2, 8/3, 4, 88/15, 28/3, 104/7, 376/15, 1904/45, 372/5, 30152/231, ...
MAPLE
b := binomial; f1 := n->if n mod 2 = 0 then 2*add(b(n, w)/(2*w+1), w=0..n/2-1)+b(n, n/2)/(n+1); else 2*add(b(n, w)/(2*w+1), w=0..(n-1)/2); fi;
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
N. J. A. Sloane, Jul 07 2003
STATUS
approved