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A138187 Hankel transform of C(2n+3,n). 1
1, -4, 3, 3, -8, 5, 5, -12, 7, 7, -16, 9, 9, -20, 11, 11, -24, 13, 13, -28, 15, 15, -32, 17, 17, -36, 19, 19, -40, 21, 21, -44, 23, 23, -48, 25, 25, -52, 27, 27, -56, 29, 29, -60, 31, 31, -64, 33, 33, -68, 35, 35, -72, 37, 37, -76, 39, 39, -80, 41 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Hankel transform of A002054(n+1). Hankel transform of A002054(n) is A057078(n+1).

Partial sums are A138188.

The sequence 1,1,-4,3,3,... has general term sum{k=0..n, C(n+k,2k)*(-1)^(n-k)*(n+k+1)}. [From Paul Barry, Apr 19 2010]

LINKS

Table of n, a(n) for n=0..59.

Index entries for linear recurrences with constant coefficients, signature (-2,-3,-2,-1).

FORMULA

G.f. : (1-2x-2x^2-x^3)/(1+x+x^2)^2;

CROSSREFS

Sequence in context: A006994 A038627 A155835 * A105342 A323601 A055525

Adjacent sequences:  A138184 A138185 A138186 * A138188 A138189 A138190

KEYWORD

easy,sign

AUTHOR

Paul Barry, Mar 04 2008

STATUS

approved

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Last modified May 12 03:08 EDT 2021. Contains 343810 sequences. (Running on oeis4.)