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A143126 a(n) = (1-2n)*2^n. 1
1, -2, -12, -40, -112, -288, -704, -1664, -3840, -8704, -19456, -43008, -94208, -204800, -442368, -950272, -2031616, -4325376, -9175040, -19398656, -40894464, -85983232, -180355072, -377487360, -788529152, -1644167168 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Hankel transform of abs(A002420) (which is 2*0^n - binomial(2n,n)/(2n-1)).

LINKS

Table of n, a(n) for n=0..25.

Index entries for linear recurrences with constant coefficients, signature (4,-4).

FORMULA

G.f.: (1-6x)/(1-2x)^2;

a(n) = Sum_{k=0..n} A121314(n,k)*(-1)^k*2^(3n-2k). - Philippe Deléham, Oct 31 2008

CROSSREFS

Cf. A118417.

Sequence in context: A290131 A008911 A005719 * A118417 A069144 A013194

Adjacent sequences:  A143123 A143124 A143125 * A143127 A143128 A143129

KEYWORD

easy,sign

AUTHOR

Paul Barry, Jul 26 2008

STATUS

approved

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Last modified January 22 20:59 EST 2022. Contains 350504 sequences. (Running on oeis4.)