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A078007 Expansion of (1-x)/(1-x-2*x^2-x^3). 3
1, 0, 2, 3, 7, 15, 32, 69, 148, 318, 683, 1467, 3151, 6768, 14537, 31224, 67066, 144051, 309407, 664575, 1427440, 3065997, 6585452, 14144886, 30381787, 65257011, 140165471, 301061280, 646649233, 1388937264, 2983297010, 6407820771, 13763352055, 29562290607 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Let X = the 3x3 matrix [0,1,0; 0,0,1; 1,2,1]. a(n) = center term of X^n; but A002478(n) = term (3,3) of X^n. - Gary W. Adamson, May 30 2008

First bisection of A058278. - Oboifeng Dira, Aug 04 2016

LINKS

Table of n, a(n) for n=0..33.

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

FORMULA

a(n) = a(n-1) + 2*a(n-2) + a(n-3). - Ilya Gutkovskiy, Aug 06 2016

PROG

(PARI) Vec((1-x)/(1-x-2*x^2-x^3)+O(x^99)) \\ Charles R Greathouse IV, Sep 26 2012

CROSSREFS

First differences of A002478.

Sequence in context: A153010 A076993 A076698 * A198683 A001932 A213920

Adjacent sequences:  A078004 A078005 A078006 * A078008 A078009 A078010

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Nov 17 2002

STATUS

approved

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Last modified January 17 23:15 EST 2019. Contains 319251 sequences. (Running on oeis4.)