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 A074582 a(n) = S(3n), where S(n) is the generalized tribonacci sequence A001644. 1
 3, 7, 39, 241, 1499, 9327, 58035, 361109, 2246915, 13980895, 86992799, 541292033, 3368061131, 20956960551, 130399710235, 811381230021, 5048627019523, 31413882696791, 195465425009943, 1216237188605169, 7567747077883259 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS G. C. Greubel, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (7,-5,1). FORMULA a(n) = 7*a(n-1) - 5*a(n-2) + a(n-3), a(0)=3, a(1)=7, a(2)=39. G.f.: (3-14*x+5*x^2)/(1-7*x+5*x^2-x^3). MATHEMATICA CoefficientList[Series[(3-14*x+5*x^2)/(1-7*x+5*x^2-x^3), {x, 0, 30}], x] PROG (PARI) my(x='x+O('x^30)); Vec((3-14*x+5*x^2)/(1-7*x+5*x^2-x^3)) \\ G. C. Greubel, Apr 13 2019 (MAGMA) R:=PowerSeriesRing(Integers(), 30); Coefficients(R!( (3-14*x+5*x^2)/(1-7*x+5*x^2-x^3) )); // G. C. Greubel, Apr 13 2019 (Sage) ((3-14*x+5*x^2)/(1-7*x+5*x^2-x^3)).series(x, 30).coefficients(x, sparse=False) # G. C. Greubel, Apr 13 2019 CROSSREFS Cf. A001644, A074581. Sequence in context: A113870 A209326 A307952 * A105621 A181081 A166895 Adjacent sequences:  A074579 A074580 A074581 * A074583 A074584 A074585 KEYWORD easy,nonn AUTHOR Mario Catalani (mario.catalani(AT)unito.it), Aug 24 2002 STATUS approved

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Last modified April 4 05:34 EDT 2020. Contains 333212 sequences. (Running on oeis4.)