cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A045624 Row sums of convolution triangle A030526.

Original entry on oeis.org

1, 11, 101, 851, 6885, 54723, 432021, 3403859, 26811397, 211225187, 1664405621, 13116776819, 103376383461, 814752361347, 6421443995733, 50610420076691, 398884119723973, 3143787312038051, 24777605586822197, 195283435452156851
Offset: 1

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Keywords

Programs

  • GAP
    a:=[1,11,101,851];; for n in [5..40] do a[n]:=17*a[n-1]-102*a[n-2] +272*a[n-3]-272*a[n-4]; od; a; # G. C. Greubel, Jan 13 2020
  • Magma
    R:=PowerSeriesRing(Integers(), 40); Coefficients(R!( x*(1-6*x+16*x^2-16*x^3)/(1-17*x+102*x^2-272*x^3 + 272*x^4) )); // G. C. Greubel, Jan 13 2020
    
  • Maple
    seq(coeff(series(x*(1-6*x+16*x^2-16*x^3)/(1-17*x+102*x^2-272*x^3 + 272*x^4), x, n+1), x, n), n = 1..40); # G. C. Greubel, Jan 13 2020
  • Mathematica
    Rest@CoefficientList[Series[x*(1-6*x+16*x^2-16*x^3)/(1-17*x+102*x^2-272*x^3 + 272*x^4), {x,0,40}], x] (* G. C. Greubel, Jan 13 2020 *)
  • PARI
    my(x='x+O('x^40)); Vec(x*(1-6*x+16*x^2-16*x^3)/(1-17*x+102*x^2-272*x^3 + 272*x^4)) \\ G. C. Greubel, Jan 13 2020
    
  • Sage
    def A045624_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( x*(1-6*x+16*x^2-16*x^3)/(1-17*x+102*x^2-272*x^3 + 272*x^4) ).list()
    a=A045624_list(40); a[1:] # G. C. Greubel, Jan 13 2020
    

Formula

G.f.: x*(1 -6*x +16*x^2 -16*x^3)/(1 -17*x +102*x^2 -272*x^3 +272*x^4) = g1(5, x)/(1-g1(5, x)), g1(5, x) := x*(1-6*x+16*x^2-16*x^3)/(1-4*x)^4 (G.f. first column of A030526).