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.

Showing 1-4 of 4 results.

A120166 a(n) = 8 + floor((2 + Sum_{j=1..n-1} a(j))/4).

Original entry on oeis.org

8, 10, 13, 16, 20, 25, 31, 39, 49, 61, 76, 95, 119, 149, 186, 232, 290, 363, 454, 567, 709, 886, 1108, 1385, 1731, 2164, 2705, 3381, 4226, 5283, 6603, 8254, 10318, 12897, 16121, 20152, 25190, 31487, 39359, 49199
Offset: 1

Views

Author

Graeme McRae, Jun 10 2006

Keywords

Crossrefs

Programs

  • Magma
    function f(n, a, b)
      t:=0;
        for k in [1..n-1] do
          t+:= a+Floor((b+t)/4);
        end for;
      return t;
    end function;
    g:= func< n, a, b | f(n+1, a, b)-f(n, a, b) >;
    A120166:= func< n | g(n, 8, 2) >;
    [A120166(n): n in [1..60]]; // G. C. Greubel, Sep 09 2023
    
  • Mathematica
    f[n_, p_, q_]:= f[n,p,q]= p +Quotient[q +Sum[f[k,p,q], {k,n-1}], 4];
    A120166[n_]:= f[n,8,2];
    Table[A120166[n], {n, 60}] (* G. C. Greubel, Sep 09 2023 *)
  • SageMath
    @CachedFunction
    def f(n, p, q): return p + (q +sum(f(k, p, q) for k in range(1, n)))//4
    def A120166(n): return f(n, 8, 2)
    [A120166(n) for n in range(1, 61)] # G. C. Greubel, Sep 09 2023

A120167 a(n) = 9 + floor((3 + Sum_{j=1..n-1} a(j))/4).

Original entry on oeis.org

9, 12, 15, 18, 23, 29, 36, 45, 56, 70, 88, 110, 137, 171, 214, 268, 335, 418, 523, 654, 817, 1021, 1277, 1596, 1995, 2494, 3117, 3896, 4870, 6088, 7610, 9512, 11890, 14863, 18579, 23223, 29029, 36286, 45358, 56697
Offset: 1

Views

Author

Graeme McRae, Jun 10 2006

Keywords

Crossrefs

Programs

  • Magma
    function f(n, a, b)
      t:=0;
        for k in [1..n-1] do
          t+:= a+Floor((b+t)/4);
        end for;
      return t;
    end function;
    g:= func< n, a, b | f(n+1, a, b)-f(n, a, b) >;
    A120167:= func< n | g(n, 9, 3) >;
    [A120167(n): n in [1..60]]; // G. C. Greubel, Sep 09 2023
    
  • Mathematica
    nxt[{t_,a_}]:=Module[{c=Floor[(39+t)/4]},{t+c,c}]; NestList[nxt,{9,9},40][[All,2]] (* Harvey P. Dale, Apr 24 2019 *)
  • SageMath
    @CachedFunction
    def f(n, p, q): return p + (q +sum(f(k, p, q) for k in range(1, n)))//4
    def A120167(n): return f(n, 9, 3)
    [A120167(n) for n in range(1, 61)] # G. C. Greubel, Sep 09 2023

A120168 a(n) = 11 + floor(Sum_{j-1..n-1} a(j)/4).

Original entry on oeis.org

11, 13, 17, 21, 26, 33, 41, 51, 64, 80, 100, 125, 156, 195, 244, 305, 381, 476, 595, 744, 930, 1163, 1453, 1817, 2271, 2839, 3548, 4435, 5544, 6930, 8663, 10828, 13535, 16919, 21149, 26436, 33045, 41306, 51633, 64541
Offset: 1

Views

Author

Graeme McRae, Jun 10 2006

Keywords

Crossrefs

Programs

  • Magma
    function f(n, a, b)
      t:=0;
        for k in [1..n-1] do
          t+:= a+Floor((b+t)/4);
        end for;
      return t;
    end function;
    g:= func< n, a, b | f(n+1, a, b)-f(n, a, b) >;
    A120168:= func< n | g(n, 11, 0) >;
    [A120168(n): n in [1..60]]; // G. C. Greubel, Sep 09 2023
    
  • Mathematica
    f[n_, p_, q_]:= f[n,p,q]= p +Quotient[q +Sum[f[k,p,q], {k,n-1}], 4];
    A120168[n_]:= f[n, 11, 0];
    Table[A120168[n], {n, 60}] (* G. C. Greubel, Sep 09 2023 *)
  • SageMath
    @CachedFunction
    def f(n, p, q): return p + (q +sum(f(k, p, q) for k in range(1, n)))//4
    def A120168(n): return f(n, 11, 0)
    [A120168(n) for n in range(1, 61)] # G. C. Greubel, Sep 09 2023

A120165 a(n) = 7 + floor((1 + Sum_{j=1..n-1} a(j))/4).

Original entry on oeis.org

7, 9, 11, 14, 17, 21, 27, 33, 42, 52, 65, 81, 102, 127, 159, 199, 248, 310, 388, 485, 606, 758, 947, 1184, 1480, 1850, 2312, 2890, 3613, 4516, 5645, 7056, 8820, 11025, 13782, 17227, 21534, 26917, 33647, 42058
Offset: 1

Views

Author

Graeme McRae, Jun 10 2006

Keywords

Crossrefs

Programs

  • Magma
    function f(n, a, b)
      t:=0;
        for k in [1..n-1] do
          t+:= a+Floor((b+t)/4);
        end for;
      return t;
    end function;
    g:= func< n, a, b | f(n+1, a, b)-f(n, a, b) >;
    A120165:= func< n | g(n, 7, 1) >;
    [A120165(n): n in [1..60]]; // G. C. Greubel, Sep 09 2023
    
  • Maple
    A[1]:= 7: S:= 7:
    for n from 2 to 100 do A[n]:= floor((29 + S)/4); S:= S + A[n] od:
    seq(A[i],i=1..100); # Robert Israel, Mar 20 2017
  • Mathematica
    a = {7}; Do[AppendTo[a, Floor[(29 + Total@ a)/4]], {i, 2, 40}]; a (* Michael De Vlieger, Mar 20 2017 *)
  • SageMath
    @CachedFunction
    def f(n, p, q): return p + (q +sum(f(k, p, q) for k in range(1, n)))//4
    def A120165(n): return f(n, 7, 1)
    [A120165(n) for n in range(1, 61)] # G. C. Greubel, Sep 09 2023

Formula

a(n) ~ c (5/4)^n with c approximately 5.5905081519. - Robert Israel, Mar 20 2017
Showing 1-4 of 4 results.