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%I #15 Jan 03 2024 08:47:02
%S 1,3,-4,2,-6,-2,-14,-18,-46,-82,-174,-338,-686,-1362,-2734,-5458,
%T -10926,-21842,-43694,-87378,-174766,-349522,-699054,-1398098,
%U -2796206,-5592402,-11184814,-22369618,-44739246,-89478482,-178956974,-357913938,-715827886
%N The main diagonal of the successive differences of A154127.
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (1, 2).
%F a(n) = a(n-1) + 2*a(n-2), n>0.
%F a(n+2) = 2*(-1)^(n+1)*A140966(n).
%F a(n+5) = -2*A083582(n).
%F a(2n+1) = 3 - A078008(2n) = 3 - A047849(n).
%F a(2n+2) = -4 - A078008(2n+1) = -4 - A020988(n).
%F G.f.: (1+2*x-9*x^2)/((1+x)*(1-2*x)). - _R. J. Mathar_, Feb 25 2009
%t f[n_]:=2/(n+1);x=6;Table[x=f[x];Numerator[x],{n,0,5!}](*Absolute Values*) (* _Vladimir Joseph Stephan Orlovsky_, Mar 12 2010 *)
%K sign
%O 0,2
%A _Paul Curtz_, Jan 12 2009
%E Edited and extended by _R. J. Mathar_, Feb 25 2009
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