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.

A170742 Expansion of g.f.: (1+x)/(1-22*x).

Original entry on oeis.org

1, 23, 506, 11132, 244904, 5387888, 118533536, 2607737792, 57370231424, 1262145091328, 27767192009216, 610878224202752, 13439320932460544, 295665060514131968, 6504631331310903296, 143101889288839872512, 3148241564354477195264, 69261314415798498295808, 1523748917147566962507776
Offset: 0

Views

Author

N. J. A. Sloane, Dec 04 2009

Keywords

Crossrefs

Programs

  • GAP
    k:=23;; Concatenation([1], List([1..25], n-> k*(k-1)^(n-1) )); # G. C. Greubel, Sep 25 2019
  • Magma
    k:=23; [1] cat [k*(k-1)^(n-1): n in [1..25]]; // G. C. Greubel, Sep 25 2019
    
  • Maple
    k:=23; seq(`if`(n=0, 1, k*(k-1)^(n-1)), n = 0..25); # G. C. Greubel, Sep 25 2019
  • Mathematica
    With[{k=23}, Table[If[n==0,1, k*(k-1)^(n-1)], {n,0,25}]] (* G. C. Greubel, Sep 25 2019 *)
    LinearRecurrence[{22},{1,23},20] (* Harvey P. Dale, Oct 13 2022 *)
  • PARI
    vector(26, n, k=23; if(n==1, 1, k*(k-1)^(n-2))) \\ G. C. Greubel, Sep 25 2019
    
  • Python
    for i in range(31):print(i,23*22**(i-1) if i>0 else 1) # Kenny Lau, Aug 01 2017
    
  • Sage
    k=23; [1]+[k*(k-1)^(n-1) for n in (1..25)] # G. C. Greubel, Sep 25 2019
    

Formula

a(n) = Sum_{k=0..n} A097805(n,k)*(-1)^(n-k)*23^k. - Philippe Deléham, Dec 04 2009
a(0) = 1; for n>0, a(n) = 23*22^(n-1). - Vincenzo Librandi, Dec 05 2009
E.g.f.: (23*exp(22*x) - 1)/22. - G. C. Greubel, Sep 25 2019