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 A087944 Expansion of (1-4*x+3*x^2)/((1-2*x)*(1-4*x+x^2)). 6
 1, 2, 6, 20, 70, 252, 922, 3404, 12630, 46988, 175066, 652764, 2434966, 9085052, 33901146, 126511340, 472127830, 1761967212, 6575675482, 24540603644, 91586476950, 341804779868, 1275631593946, 4760719498764, 17767242206806 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Binomial transform of A052948. LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (6,-9,2). FORMULA a(0)=1, a(2)=2, a(2)=6, a(n) = 6*a(n-1)-9*a(n-2)+2*a(n-3), n>2. a(n) = (2^n+(2+sqrt(3))^n+(2-sqrt(3))^n)/3. MATHEMATICA CoefficientList[Series[(1-4x+3x^2)/((1-2x)(1-4x+x^2)), {x, 0, 30}], x] (* or *) LinearRecurrence[{6, -9, 2}, {1, 2, 6}, 30] (* Harvey P. Dale, Feb 09 2013 *) CROSSREFS Cf. A052948. Sequence in context: A065345 A130914 A302644 * A056616 A065346 A302645 Adjacent sequences: A087941 A087942 A087943 * A087945 A087946 A087947 KEYWORD easy,nonn AUTHOR Paul Barry, Sep 16 2003 STATUS approved

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Last modified June 2 14:21 EDT 2023. Contains 363097 sequences. (Running on oeis4.)