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 A084860 Expansion of (1-2x+2x^2-x^3)/(1-2x)^2. 4

%I

%S 1,2,6,15,36,84,192,432,960,2112,4608,9984,21504,46080,98304,208896,

%T 442368,933888,1966080,4128768,8650752,18087936,37748736,78643200,

%U 163577856,339738624,704643072,1459617792,3019898880,6241124352

%N Expansion of (1-2x+2x^2-x^3)/(1-2x)^2.

%C Partial sums are A084858. Partial sums of A084860.

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (4,-4).

%F a(0)=1, a(n+1)=3*2^(n-2)(n+3)-0^n/4.

%F Equals binomial transform of nonzero terms of A026741: (1, 1, 3, 2, 5, 3, 7, 4,...). - _Gary W. Adamson_, Apr 25 2008

%F Equals row sums of triangle A139633 - _Gary W. Adamson_, Apr 27 2008

%t CoefficientList[Series[(1-2x+2x^2-x^3)/(1-2x)^2,{x,0,50}],x] (* _Harvey P. Dale_, Mar 30 2011 *)

%Y Cf. A026741.

%Y Cf. A139633.

%K easy,nonn

%O 0,2

%A _Paul Barry_, Jun 12 2003

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Last modified February 21 03:06 EST 2019. Contains 320364 sequences. (Running on oeis4.)