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 A156096 Inverse binomial transform of A030186. 2

%I

%S 1,1,4,6,18,32,84,164,400,824,1928,4096,9360,20240,45632,99680,223008,

%T 489984,1091392,2405952,5345536,11806592,26194048,57917440,128389376,

%U 284057856,629392384,1393010176,3085685248,6830825472,15128761344

%N Inverse binomial transform of A030186.

%C A030186 = (1, 2, 7, 22, 71, 228, 733, 2356, 7573, 24342, ...).

%H G. C. Greubel, <a href="/A156096/b156096.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (0,4,2).

%F a(n) = A007318^(-1) * A030186

%F From _R. J. Mathar_, Feb 10 2009: (Start)

%F a(n) = 4*a(n-2) + 2*a(n-3).

%F G.f.: (1+x)/(1-4*x^2-2*x^3). (End)

%e a(3) = 6 = (-1, 3, -3, 1) dot (1, 2, 7, 22) = (-1, 6, -21, 22) = 6.

%p seq(coeff(series((1+x)/(1-4*x^2-2*x^3), x, n+1), x, n), n = 0..40); # _G. C. Greubel_, Oct 27 2019

%t LinearRecurrence[{0,4,2},{1,1,4},40] (* _Harvey P. Dale_, Apr 05 2014 *)

%o (PARI) my(x='x+O('x^40)); Vec((1+x)/(1-4*x^2-2*x^3)) \\ _G. C. Greubel_, Oct 27 2019

%o (MAGMA) R<x>:=PowerSeriesRing(Integers(), 40); Coefficients(R!( (1+x)/(1-4*x^2-2*x^3) )); // _G. C. Greubel_, Oct 27 2019

%o (Sage)

%o def A156096_list(prec):

%o P.<x> = PowerSeriesRing(ZZ, prec)

%o return P((1+x)/(1-4*x^2-2*x^3)).list()

%o A156096_list(40) # _G. C. Greubel_, Oct 27 2019

%o (GAP) a:=[1,1,4];; for n in [4..40] do a[n]:=4*a[n-2]+2*a[n-3]; od; a; # _G. C. Greubel_, Oct 27 2019

%Y Cf. A030186.

%K nonn

%O 0,3

%A _Gary W. Adamson_, Feb 03 2009

%E More terms from _R. J. Mathar_, Feb 10 2009

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Last modified June 20 04:43 EDT 2021. Contains 345157 sequences. (Running on oeis4.)