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 A134142 List of quadruples: 2*(-4)^n, -3*(-4)^n, 2*(-4^n), 2*(-4)^n, n >= 0. 3
 2, -3, 2, 2, -8, 12, -8, -8, 32, -48, 32, 32, -128, 192, -128, -128, 512, -768, 512, 512, -2048, 3072, -2048, -2048, 8192, -12288, 8192, 8192, -32768, 49152, -32768, -32768, 131072, -196608, 131072, 131072, -524288, 786432, -524288, -524288, 2097152, -3145728, 2097152, 2097152, -8388608 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS Table of n, a(n) for n=0..44. FORMULA 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 a(n) = (1 - I/2)*(-1 - I)^n + (1 + I/2)*(-1 + I)^n, n>=0. - Taras Goy, Apr 20 2019 MAPLE 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 CROSSREFS Cf. A081147, A134654. Sequence in context: A154179 A300862 A151863 * A353390 A298310 A138680 Adjacent sequences: A134139 A134140 A134141 * A134143 A134144 A134145 KEYWORD tabf,easy,sign AUTHOR Paul Curtz, Jan 29 2008 EXTENSIONS More terms from R. J. Mathar, Feb 05 2008 STATUS approved

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Last modified June 2 15:21 EDT 2023. Contains 363098 sequences. (Running on oeis4.)