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A116391 Expansion of 1/((1+x)(sqrt(1-4x^2)-x)). 1
1, 0, 3, 2, 11, 14, 47, 78, 217, 408, 1039, 2086, 5065, 10560, 24931, 53194, 123403, 267222, 612903, 1340222, 3050679, 6714946, 15205967, 33622158, 75864835, 168275790, 378743151, 841959974, 1891648931, 4211866694, 9450828951 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

COMMENTS

Diagonal sums of A116389.

FORMULA

a(n)=sum{k=0..floor(n/2),sum{j=0..k, C(k,j)(-1)^(k-j)*sum{i=0..floor((n-k)/2), C(i+(j-1)/2,i)C(j,n-k-2i)4^i}}}

CROSSREFS

Sequence in context: A194608 A052973 A087956 * A087629 A178384 A078563

Adjacent sequences:  A116388 A116389 A116390 * A116392 A116393 A116394

KEYWORD

easy,nonn

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Feb 12 2006

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Last modified February 16 01:56 EST 2012. Contains 205860 sequences.