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.

A074825 Binomial transform of reflected pentanacci numbers A074062: a(n) = Sum_{k=0..n} binomial(n,k)*A074062(k).

Original entry on oeis.org

5, 4, 2, -2, -10, -16, -4, 46, 142, 250, 262, 4, -652, -1530, -1818, 38, 5662, 14760, 22028, 15014, -22490, -95846, -172434, -154740, 110500, 733134, 1556206, 1875238, 365334, -4306496, -11734244, -17112802, -9496002, 25050298, 90586134, 157886356, 142006676, -87803882
Offset: 0

Views

Author

Mario Catalani (mario.catalani(AT)unito.it), Sep 09 2002

Keywords

Crossrefs

Cf. A074062.

Programs

  • Magma
    I:=[5,4,2,-2,-10]; [n le 5 select I[n] else 4*Self(n-1) -7*Self(n-2) +6*Self(n-3) -3*Self(n-4) +2*Self(n-5): n in [1..51]]; // G. C. Greubel, Jul 05 2021
    
  • Mathematica
    CoefficientList[Series[(5-16x+21x^2-12x^3+3x^4)/(1-4x+7x^2-6x^3+3x^4-2x^5), {x, 0, 40}], x]
    LinearRecurrence[{4,-7,6,-3,2},{5,4,2,-2,-10},40] (* Harvey P. Dale, Nov 29 2019 *)
  • Sage
    def A074825_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( (5-16*x+21*x^2-12*x^3+3*x^4)/(1-4*x+7*x^2-6*x^3+3*x^4-2*x^5) ).list()
    A074825_list(50) # G. C. Greubel, Jul 05 2021

Formula

a(n) = 4*a(n-1) - 7*a(n-2) + 6*a(n-3) - 3*a(n-4) + 2*a(n-5), a(0)=5, a(1)=4, a(2)=2, a(3)=-2, a(4)=-10.
G.f.: (5 -16*x +21*x^2 -12*x^3 +3*x^4)/(1 -4*x +7*x^2 -6*x^3 +3*x^4 -2*x^5).