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%I #11 Apr 20 2019 07:45:07
%S 2,-3,2,2,-8,12,-8,-8,32,-48,32,32,-128,192,-128,-128,512,-768,512,
%T 512,-2048,3072,-2048,-2048,8192,-12288,8192,8192,-32768,49152,-32768,
%U -32768,131072,-196608,131072,131072,-524288,786432,-524288,-524288,2097152,-3145728,2097152,2097152,-8388608
%N List of quadruples: 2*(-4)^n, -3*(-4)^n, 2*(-4^n), 2*(-4)^n, n >= 0.
%F O.g.f.: (x+2)/(2*x^2+2*x+1). a(n) = 2*A108520(n)+A108520(n-1). - _R. J. Mathar_, Feb 05 2008
%F a(n) = (1 - I/2)*(-1 - I)^n + (1 + I/2)*(-1 + I)^n, n>=0. - _Taras Goy_, Apr 20 2019
%p A134142 := proc(n) (-4)^floor(n/4)*op(1+(n mod 4), [2,-3,2,2]) ; end: for n from 0 to 80 do printf("%d ",A134142(n)) ; od: # _R. J. Mathar_, Feb 05 2008
%Y Cf. A081147, A134654.
%K tabf,easy,sign
%O 0,1
%A _Paul Curtz_, Jan 29 2008
%E More terms from _R. J. Mathar_, Feb 05 2008
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