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.

A298271 Expansion of x/((1 - x)*(1 - 322*x + x^2)).

Original entry on oeis.org

0, 1, 323, 104006, 33489610, 10783550415, 3472269744021, 1118060074024348, 360011871566096036, 115922704584208899245, 37326750864243699460855, 12019097855581887017496066, 3870112182746503375934272398, 1246164103746518505163818216091
Offset: 0

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Author

Bruno Berselli, Jan 16 2018

Keywords

Crossrefs

Programs

  • Mathematica
    CoefficientList[x/((1 - x) (1 - 322 x + x^2)) + O[x]^20, x]
  • Maxima
    makelist(coeff(taylor(x/((1-x)*(1-322*x+x^2)), x, 0, n), x, n), n, 0, 20);
    
  • PARI
    a(n)=([0,1,0; 0,0,1; 1,-323,323]^n*[0;1;323])[1,1] \\ Charles R Greathouse IV, Jan 18 2018
    
  • PARI
    concat(0, Vec(x / ((1 - x)*(1 - 322*x + x^2)) + O(x^15))) \\ Colin Barker, Jan 19 2018
  • Sage
    gf = x/((1-x)*(1-322*x+x^2))
    print(taylor(gf, x, 0, 20).list())
    

Formula

G.f.: x/((1 - x)*(1 - 322*x + x^2)).
a(n) = a(-n-1) = 323*a(n-1) - 323*a(n-2) + a(n-3).
a(n) = (1/5760)*((2 + sqrt(5))^(4*n+2) + (2 + sqrt(5))^-(4*n+2) - 18).
a(n) = A298101(n) - A298101(n-1) + A298101(n-2) - A298101(n-3) + ..., hence:
a(n) + a(n-1) = A298101(n).
a(n) - a(n-1) = (1/144)*Fibonacci(12*n).
a(n) - a(n-2) = (1/8)*Fibonacci(12*n-6).
a(n)*a(n-2) = a(n-1)*(a(n-1) - 1).
Sum_{j>1} 1/a(j) = 161 - 72*sqrt(5) = A094214^12.
a(n) = A157459(n+1)/72. - Greg Dresden, Dec 02 2021