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A077930 Expansion of (1-x)^(-1)/(1+2*x+x^2+x^3). 5
1, -1, 2, -3, 6, -10, 18, -31, 55, -96, 169, -296, 520, -912, 1601, -2809, 4930, -8651, 15182, -26642, 46754, -82047, 143983, -252672, 443409, -778128, 1365520, -2396320, 4205249, -7379697, 12950466, -22726483, 39882198, -69988378, 122821042, -215535903, 378239143, -663763424 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Signed version of A060945: a(n) = (-1)^n * A060945(n).

LINKS

Table of n, a(n) for n=0..37.

Index entries for linear recurrences with constant coefficients, signature (-1,1,0,1).

FORMULA

a(n+1)-a(n) = (-1)^(n+1)*A005314(n+2). - R. J. Mathar, Mar 14 2011

a(0)=1, a(1)=-1, a(2)=2, a(3)=-3, a(n)=-a(n-1)+a(n-2)+a(n-4). - Harvey P. Dale, Feb 20 2013

MATHEMATICA

CoefficientList[Series[1/(1-x)/(1+2x+x^2+x^3), {x, 0, 50}], x] (* or *) LinearRecurrence[ {-1, 1, 0, 1}, {1, -1, 2, -3}, 50] (* Harvey P. Dale, Feb 20 2013 *)

PROG

(PARI) Vec((1-x)^(-1)/(1+2*x+x^2+x^3)+O(x^99)) \\ Charles R Greathouse IV, Sep 24 2012

CROSSREFS

All of A060945, A077930, A181532 are variations of the same sequence. - N. J. A. Sloane, Mar 04 2012

Sequence in context: A172516 A102702 A181532 * A060945 A023359 A082482

Adjacent sequences:  A077927 A077928 A077929 * A077931 A077932 A077933

KEYWORD

sign,easy

AUTHOR

N. J. A. Sloane, Nov 17 2002

STATUS

approved

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Last modified April 17 08:40 EDT 2021. Contains 343064 sequences. (Running on oeis4.)