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 1-7 of 7 results.

A081129 Differences of Beatty sequence for cube root of 3.

Original entry on oeis.org

1, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 1, 2
Offset: 0

Views

Author

Benoit Cloitre, Apr 16 2003

Keywords

Crossrefs

Programs

  • Magma
    A081129:= func< n | Floor((n+1)*3^(1/3)) - Floor(n*3^(1/3)) >;
    [A081129(n): n in [0..120]]; // G. C. Greubel, Jan 15 2024
    
  • Mathematica
    Differences[Floor[Range[0,110]Surd[3,3]]] (* Harvey P. Dale, Apr 06 2022 *)
  • PARI
    a(n)=floor((n+1)*3^(1/3))-floor(n*3^(1/3))
    
  • SageMath
    def A081129(n): return floor((n+1)*3^(1/3)) - floor(n*3^(1/3))
    [A081129(n) for n in range(121)] # G. C. Greubel, Jan 15 2024

Formula

a(n) = floor((n+1)*3^(1/3)) - floor(n*3^(1/3)).

A038129 Beatty sequence for cube root of 2.

Original entry on oeis.org

0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18, 20, 21, 22, 23, 25, 26, 27, 28, 30, 31, 32, 34, 35, 36, 37, 39, 40, 41, 42, 44, 45, 46, 47, 49, 50, 51, 52, 54, 55, 56, 57, 59, 60, 61, 62, 64, 65, 66, 68, 69, 70, 71, 73, 74, 75, 76, 78, 79, 80, 81, 83, 84, 85, 86, 88, 89
Offset: 0

Views

Author

Keywords

Crossrefs

Cf. A059539.

Programs

  • Mathematica
    Floor[Range[0,90]Surd[2,3]] (* Harvey P. Dale, Mar 24 2019 *)
  • PARI
    a(n)=floor(n*2^(1/3))
    
  • Python
    from sympy import integer_nthroot
    def A038129(n): return integer_nthroot(2*n**3,3)[0] # Chai Wah Wu, Mar 17 2021

Formula

a(n)=floor(n*1.2599210498..)
a(n)=floor(n*2^(1/3)) - Benoit Cloitre, Apr 16 2003

Extensions

More terms from Benoit Cloitre, Apr 16 2003

A059540 Beatty sequence for 3^(1/3)/(3^(1/3)-1).

Original entry on oeis.org

3, 6, 9, 13, 16, 19, 22, 26, 29, 32, 35, 39, 42, 45, 48, 52, 55, 58, 61, 65, 68, 71, 75, 78, 81, 84, 88, 91, 94, 97, 101, 104, 107, 110, 114, 117, 120, 123, 127, 130, 133, 136, 140, 143, 146, 150, 153, 156, 159, 163, 166, 169, 172, 176, 179, 182, 185, 189, 192
Offset: 1

Views

Author

Mitch Harris, Jan 22 2001

Keywords

Crossrefs

Beatty complement is A059539.
Cf. A072365.

Programs

  • Mathematica
    Floor[Range[100]/(1 - 3^(-1/3))] (* Paolo Xausa, Jul 17 2024 *)
  • PARI
    { default(realprecision, 100); b=3^(1/3)/(3^(1/3) - 1); for (n = 1, 2000, write("b059540.txt", n, " ", floor(n*b)); ) } \\ Harry J. Smith, Jun 28 2009

Formula

a(n) = floor(n/(1 - A072365)). - Paolo Xausa, Jul 17 2024

A248188 Numbers k such that A248186(k+1) = A248186(k) + 1.

Original entry on oeis.org

4, 5, 7, 8, 10, 11, 12, 14, 15, 17, 18, 20, 21, 23, 24, 25, 27, 28, 30, 31, 33, 34, 36, 37, 38, 40, 41, 43, 44, 46, 47, 49, 50, 51, 53, 54, 56, 57, 59, 60, 62, 63, 64, 66, 67, 69, 70, 72, 73, 74, 76, 77, 79, 80, 82, 83, 85, 86, 87, 89, 90, 92, 93, 95, 96, 98
Offset: 1

Views

Author

Clark Kimberling, Oct 04 2014

Keywords

Comments

a(n) = A059539(n+2) = [3^(1/3)*(n+2)] for n = 1..655, but a(656) = 948 = A059539(658)-1.

Examples

			The difference sequence of A248186 is (0, 0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, ...), so that A248187 = (1, 2, 3, 6, 9, 13, 16, 19, 22,...) and A248188 = (4, 5, 7, 8, 10, 11, 12, 14, 15, 17,...), the complement of A248186.
		

Crossrefs

Programs

  • Mathematica
    $MaxExtraPrecision = Infinity;
    z = 800; p[k_] := p[k] = Sum[1/(h*(h + 1)*(h + 2)*(h + 3)), {h, 1, k}];
    N[Table[1/18 - p[n], {n, 1, z/10}]]
    f[n_] := f[n] = Select[Range[z], 1/18 - p[#] < 1/n^3 &, 1]
    u = Flatten[Table[f[n], {n, 1, z}]]   (* A248186 *)
    Flatten[Position[Differences[u], 0]]  (* A248187 *)
    Flatten[Position[Differences[u], 1]]  (* A248188 *)

A187574 Rank transform of the sequence floor(n*3^(1/3)); complement of A187575.

Original entry on oeis.org

1, 3, 5, 6, 9, 10, 12, 14, 15, 17, 19, 21, 23, 25, 26, 28, 30, 31, 34, 35, 37, 39, 41, 42, 45, 46, 48, 50, 51, 54, 55, 57, 59, 61, 62, 64, 66, 67, 70, 71, 73, 75, 77, 79, 80, 82, 84, 86, 87, 90, 91, 93, 95, 96, 98, 100, 102, 104, 106, 107, 109, 111, 112, 115, 116, 118, 120, 122, 124, 125, 127, 129, 131, 132, 135, 136, 138, 140, 142, 143, 145, 147, 149, 151, 152, 154, 156, 158, 160
Offset: 1

Views

Author

Clark Kimberling, Mar 11 2011

Keywords

Comments

See A187224.

Crossrefs

Programs

  • Mathematica
    seqA = Table[Floor[n*3^(1/3)], {n, 1, 220}] (*A059539*)
    seqB = Table[n, {n, 1, 220}];(*A000027*)
    jointRank[{seqA_,
       seqB_}] := {Flatten@Position[#1, {_, 1}],
        Flatten@Position[#1, {_, 2}]} &[
      Sort@Flatten[{{#1, 1} & /@ seqA, {#1, 2} & /@ seqB}, 1]];
    limseqU =
    FixedPoint[jointRank[{seqA, #1[[1]]}] &,
       jointRank[{seqA, seqB}]][[1]] (*A187574*)
    Complement[Range[Length[seqA]], limseqU]  (*A187575*)
    (* Peter J. C. Moses, Mar 11 2011 *)

A307513 Beatty sequence for 1/log(2).

Original entry on oeis.org

1, 2, 4, 5, 7, 8, 10, 11, 12, 14, 15, 17, 18, 20, 21, 23, 24, 25, 27, 28, 30, 31, 33, 34, 36, 37, 38, 40, 41, 43, 44, 46, 47, 49, 50, 51, 53, 54, 56, 57, 59, 60, 62, 63, 64, 66, 67, 69, 70, 72, 73, 75, 76, 77, 79, 80, 82, 83, 85, 86, 88, 89, 90, 92, 93, 95, 96, 98, 99, 100, 102, 103, 105, 106, 108, 109, 111, 112, 113, 115
Offset: 1

Views

Author

R. J. Mathar, Apr 12 2019

Keywords

Comments

Very similar to A059539 because A002581 is close to A007525.

Crossrefs

Cf. A007525.

Formula

a(n) = floor(n*A007525).
A166986(n) = 2*a(n+2)-4.

A249179 First row of spectral array W(3^(1/3)).

Original entry on oeis.org

1, 3, 4, 9, 12, 29, 41, 94, 135, 306, 441, 997, 1437, 3251, 4688, 10602, 15290, 34574, 49864, 112751, 162615, 367699, 530313, 1199127, 1729440, 3910553, 5639993, 12752965
Offset: 1

Views

Author

Colin Barker, Dec 03 2014

Keywords

Comments

3^(1/3) = 1.442249570307408382321638310780109588391869253499350577546416...
The sequence is generated from the Beatty sequence (A059539) and from the complement of the Beatty sequence (A059540) for 3^(1/3).

Crossrefs

Programs

  • PARI
    \\ Row i of the generalized Wythoff array W(h),
    \\   where h is an irrational number between 1 and 2,
    \\   and m is the number of terms in the vectors b and c.
    row(h, i, m) = {
      if(h<=1 || h>=2, print("Invalid value for h"); return);
      my(
        b=vector(m, n, floor(n*h)),       \\ Beatty sequence for h
        c=vector(m, n, floor(n*h/(h-1))), \\ Complement of b
        w=[b[b[i]], c[b[i]]],
        j=3
      );
      while(1,
        if(j%2==1,
          if(w[j-1]<=#b, w=concat(w, b[w[j-1]]), return(w))
        ,
          if(w[j-2]<=#c, w=concat(w, c[w[j-2]]), return(w))
        );
        j++
      )
    }
    allocatemem(10^9)
    default(realprecision, 100)
    row(3^(1/3), 1, 10^7)
Showing 1-7 of 7 results.