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A110199 Sum C(k), k=0..floor(n/2). 1
1, 1, 2, 2, 4, 4, 9, 9, 23, 23, 65, 65, 197, 197, 626, 626, 2056, 2056, 6918, 6918, 23714, 23714, 82500, 82500, 290512, 290512, 1033412, 1033412, 3707852, 3707852, 13402697, 13402697, 48760367, 48760367, 178405157, 178405157, 656043857 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

COMMENTS

Hankel transform is A166446(n+2). [From Paul Barry (pbarry(AT)wit.ie), Jun 23 2010]

FORMULA

G.f.: (1-sqrt(1-4x^2))/((1-x)2x^2); a(n)=sum{k=0..floor(n/2), binomial(2k, k)/(k+1)}.

MAPLE

a:=n->sum(binomial(2*j, j)/(j+1), j=0..n): seq(a(n/2), n=0..36); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 30 2007

CROSSREFS

Cf. A014137.

Sequence in context: A118406 A072488 A074818 * A053656 A035054 A099537

Adjacent sequences:  A110196 A110197 A110198 * A110200 A110201 A110202

KEYWORD

easy,nonn

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Jul 15 2005

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Last modified February 17 14:50 EST 2012. Contains 206050 sequences.