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A128058 Expansion of 1/((1-x)sqrt(1-2x+5x^2)). 2
1, 2, 1, -4, -9, 2, 43, 72, -53, -418, -549, 860, 4161, 4006, -11619, -41104, -24989, 145046, 399571, 89796, -1723259, -3787914, 829841, 19739016, 34642741, -26909998, -219300587, -300591148, 467328447, 2369124842 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Partial sums of A098331. Binomial transform of A128057. Hankel transform is A128056.

LINKS

Table of n, a(n) for n=0..29.

FORMULA

a(n)=sum{k=0..n, sum{j=0..k, C(k,j)*C(k-j,j)*(-1)^j}}

CROSSREFS

Sequence in context: A183244 A086933 A077878 * A163236 A077160 A228043

Adjacent sequences:  A128055 A128056 A128057 * A128059 A128060 A128061

KEYWORD

easy,sign

AUTHOR

Paul Barry, Feb 13 2007

STATUS

approved

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Last modified December 9 17:46 EST 2016. Contains 278985 sequences.