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 A123879 Expansion of (1-2*x+2*x^2-x^3)/(1-3*x+5*x^2-3*x^3+x^4). 2
 1, 1, 0, -3, -7, -7, 5, 32, 57, 33, -95, -311, -416, -11, 1209, 2745, 2573, -2368, -12943, -22015, -11007, 40593, 123712, 157165, -14279, -498119, -1075179, -934944, 1090985, 5220257, 8476193, 3535193, -17205600 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS Row sums of number triangle A123878. LINKS G. C. Greubel, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (3,-5,3,-1). FORMULA a(n) = Sum_{k=0..n} Sum_{j=0..n} (-1)^(j-k)*C(n+j,2*j)*C(j+k,2*k). MAPLE seq(coeff(series((1-2*x+2*x^2-x^3)/(1-3*x+5*x^2-3*x^3+x^4), x, n+1), x, n), n = 0 .. 40); # G. C. Greubel, Aug 08 2019 MATHEMATICA LinearRecurrence[{3, -5, 3, -1}, {1, 1, 0, -3}, 40] (* G. C. Greubel, Aug 08 2019 *) PROG (PARI) my(x='x+O('x^40)); Vec((1-2*x+2*x^2-x^3)/(1-3*x+5*x^2-3*x^3+x^4)) \\ G. C. Greubel, Aug 08 2019 (MAGMA) R:=PowerSeriesRing(Integers(), 40); Coefficients(R!( (1-2*x+2*x^2-x^3)/(1-3*x+5*x^2-3*x^3+x^4) )); // G. C. Greubel, Aug 08 2019 (Sage) def A123879_list(prec):     P. = PowerSeriesRing(ZZ, prec)     return P((1-2*x+2*x^2-x^3)/(1-3*x+5*x^2-3*x^3+x^4)).list() A123879_list(40) # G. C. Greubel, Aug 08 2019 (GAP) a:=[1, 1, 0, -3];; for n in [5..40] do a[n]:=3*a[n-1]-5*a[n-2]+3*a[n-3]-a[n-4]; od; a; # G. C. Greubel, Aug 08 2019 CROSSREFS Cf. A123878, A123880. Sequence in context: A197476 A246848 A019634 * A193016 A325894 A176269 Adjacent sequences:  A123876 A123877 A123878 * A123880 A123881 A123882 KEYWORD easy,sign AUTHOR Paul Barry, Oct 16 2006 STATUS approved

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Last modified September 20 05:51 EDT 2019. Contains 327212 sequences. (Running on oeis4.)