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 1-10 of 23 results. Next

A276870 First differences of the Beatty sequence A110117 for sqrt(2) + sqrt(3).

Original entry on oeis.org

3, 3, 3, 3, 3, 3, 4, 3, 3, 3, 3, 3, 3, 4, 3, 3, 3, 3, 3, 3, 4, 3, 3, 3, 3, 3, 3, 4, 3, 3, 3, 3, 3, 3, 4, 3, 3, 3, 3, 3, 3, 4, 3, 3, 3, 3, 3, 4, 3, 3, 3, 3, 3, 3, 4, 3, 3, 3, 3, 3, 3, 4, 3, 3, 3, 3, 3, 3, 4, 3, 3, 3, 3, 3, 3, 4, 3, 3, 3, 3, 3, 3, 4, 3, 3, 3
Offset: 1

Views

Author

Clark Kimberling, Sep 26 2016

Keywords

Crossrefs

Programs

  • Magma
    [Floor(n*(Sqrt(2) + Sqrt(3))) - Floor((n-1)*(Sqrt(2) + Sqrt(3))): n in [1..100]]; // G. C. Greubel, Aug 16 2018
  • Mathematica
    z = 500; r = Sqrt[2]+Sqrt[3]; b = Table[Floor[k*r], {k, 0, z}] (* A110117 *)
    Differences[b] (* A276870 *)
  • PARI
    vector(100, n, floor(n*(sqrt(2) + sqrt(3))) - floor((n-1)*(sqrt(2)+sqrt(3)))) \\ G. C. Greubel, Aug 16 2018
    

Formula

a(n) = floor(n*r) - floor(n*r - r), where r = sqrt(2) + sqrt(3), n >= 1.

A276871 Sums-complement of the Beatty sequence for sqrt(5).

Original entry on oeis.org

1, 10, 19, 28, 37, 48, 57, 66, 75, 86, 95, 104, 113, 124, 133, 142, 151, 162, 171, 180, 189, 198, 209, 218, 227, 236, 247, 256, 265, 274, 285, 294, 303, 312, 323, 332, 341, 350, 359, 370, 379, 388, 397, 408, 417, 426, 435, 446, 455, 464, 473, 484, 493, 502
Offset: 1

Views

Author

Clark Kimberling, Sep 24 2016

Keywords

Comments

The sums-complement of a sequence s(1), s(2), ... of positive integers is introduced here as the set of numbers c(1), c(2), ... such that no c(n) is a sum s(j)+s(j+1)+...+s(k) for any j and k satisfying 1 <= j <= k. If this set is not empty, the term "sums-complement" also applies to the (possibly finite) sequence of numbers c(n) arranged in increasing order. In particular, the difference sequence D(r) of a Beatty sequence B(r) of an irrational number r > 2 has an infinite sums-complement, abbreviated as SC(r) in the following table:
r B(r) D(r) SC(r)
----------------------------------------------------
2+sqrt(1/2) A182769 A276869 A276888
sqrt(2)+sqrt(3) A110117 A276870 A276889
From Jeffrey Shallit, Aug 15 2023: (Start)
Simpler description: this sequence represents those positive integers that CANNOT be expressed as a difference of two elements of A022839.
There is a 20-state Fibonacci automaton for the terms of this sequence (see a276871.pdf). It takes as input the Zeckendorf representation of n and accepts iff n is a member of A276871. (End)

Examples

			The Beatty sequence for sqrt(5) is A022839 = (0,2,4,6,8,11,13,15,...), with difference sequence s = A081427 = (2,2,2,2,3,2,2,2,3,2,...).  The sums s(j)+s(j+1)+...+s(k) include (2,3,4,5,6,7,8,9,11,12,...), with complement (1,10,19,28,37,...).
		

Crossrefs

Programs

  • Mathematica
    z = 500; r = Sqrt[5]; b = Table[Floor[k*r], {k, 0, z}]; (* A022839 *)
    t = Differences[b]; (* A081427 *)
    c[k_, n_] := Sum[t[[i]], {i, n, n + k - 1}];
    u[k_] := Union[Table[c[k, n], {n, 1, z - k + 1}]];
    w = Flatten[Table[u[k], {k, 1, z}]]; Complement[Range[Max[w]], w];  (* A276871 *)

A172332 Floor(n*(sqrt(13)+sqrt(5))).

Original entry on oeis.org

0, 5, 11, 17, 23, 29, 35, 40, 46, 52, 58, 64, 70, 75, 81, 87, 93, 99, 105, 110, 116, 122, 128, 134, 140, 146, 151, 157, 163, 169, 175, 181, 186, 192, 198, 204, 210, 216, 221, 227, 233, 239, 245, 251, 257, 262, 268, 274, 280, 286, 292
Offset: 0

Views

Author

Vincenzo Librandi, Feb 01 2010

Keywords

Comments

Also integer part of n*5.8416192529..., where the constant is the largest root of x^4 -36*x^2 +64.

Crossrefs

Programs

  • Magma
    [Floor(n*(Sqrt(13)+Sqrt(5))): n in [0..60]];
  • Mathematica
    With[{c = Sqrt[13] + Sqrt[5]}, Floor[c Range[0, 70]]] (* Vincenzo Librandi, Aug 01 2013 *)

A172334 Floor(n*(sqrt(13)+sqrt(3))).

Original entry on oeis.org

0, 5, 10, 16, 21, 26, 32, 37, 42, 48, 53, 58, 64, 69, 74, 80, 85, 90, 96, 101, 106, 112, 117, 122, 128, 133, 138, 144, 149, 154, 160, 165, 170, 176, 181, 186, 192, 197, 202, 208, 213, 218, 224, 229, 234, 240, 245, 250, 256, 261, 266
Offset: 0

Views

Author

Vincenzo Librandi, Feb 01 2010

Keywords

Comments

Also integer part of n*5.3376020830..., where the constant is the largest root of x^4 -32*x^2 +100.

Crossrefs

Programs

  • Magma
    [ Floor(n*(Sqrt(13)+Sqrt(3))): n in [0..60] ];
  • Mathematica
    With[{c = Sqrt[13] + Sqrt[3]}, Table[Floor[c n], {n, 0, 50}]] (* Harvey P. Dale, Apr 25 2011 *)

A172336 a(n) = floor(n*(sqrt(13)+sqrt(2))).

Original entry on oeis.org

0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 256, 261, 266, 271, 276
Offset: 0

Views

Author

Vincenzo Librandi, Feb 01 2010

Keywords

Comments

a(n) = integer part of n*(sqrt(13)+sqrt(2)), where the constant is the largest root of x^4 -30*x^2 +121.

Crossrefs

Programs

  • Magma
    [Floor(n*(Sqrt(13)+Sqrt(2))): n in [0..60]];
    
  • Mathematica
    With[{c = Sqrt[13] + Sqrt[2]}, Floor[c Range[0, 70]]] (* Vincenzo Librandi, Aug 01 2013 *)
  • PARI
    for(n=0,50, print1(floor(n*(sqrt(13)+sqrt(2))), ", ")) \\ G. C. Greubel, Jul 05 2017

A172338 a(n) = floor(n*(sqrt(5)+sqrt(3))).

Original entry on oeis.org

0, 3, 7, 11, 15, 19, 23, 27, 31, 35, 39, 43, 47, 51, 55, 59, 63, 67, 71, 75, 79, 83, 87, 91, 95, 99, 103, 107, 111, 115, 119, 123, 126, 130, 134, 138, 142, 146, 150, 154, 158, 162, 166, 170, 174, 178, 182, 186, 190, 194, 198, 202, 206, 210, 214, 218
Offset: 0

Views

Author

Vincenzo Librandi, Feb 01 2010

Keywords

Comments

sqrt(5)+sqrt(3) = 3.96811878506867... is the largest root of x^4 - 16*x^2 + 4.

Crossrefs

Programs

  • Magma
    [Floor(n*Sqrt(5)+Sqrt(3)): n in [0..60] ];
    
  • Mathematica
    With[{c = Sqrt[5] + Sqrt[3]}, Floor[c Range[0,60]]] (* Harvey P. Dale, Apr 10 2012 *)
  • PARI
    a(n)=sqrtint(sqrtint(60*n^4)+8*n^2) \\ Charles R Greathouse IV, Jan 24 2022

A110118 a(n) = floor(n*(sqrt(6) + sqrt(2) + 2)/4).

Original entry on oeis.org

1, 2, 4, 5, 7, 8, 10, 11, 13, 14, 16, 17, 19, 20, 21, 23, 24, 26, 27, 29, 30, 32, 33, 35, 36, 38, 39, 41, 42, 43, 45, 46, 48, 49, 51, 52, 54, 55, 57, 58, 60, 61, 63, 64, 65, 67, 68, 70, 71, 73, 74, 76, 77, 79, 80, 82, 83, 85, 86, 87, 89, 90, 92, 93, 95, 96, 98, 99, 101, 102
Offset: 1

Views

Author

Reinhard Zumkeller, Jul 13 2005

Keywords

Comments

Beatty sequence for (sqrt(6)+sqrt(2)+2)/4 = 1.465925826289...; complement of A110117.

Crossrefs

Cf. A110119.

Programs

  • Magma
    [Floor(n*(Sqrt(6) + Sqrt(2) + 2)/4): n in [1..100]]; // G. C. Greubel, Mar 27 2018
  • Mathematica
    With[{c = (Sqrt[2] + Sqrt[6] + 2)/4}, Floor[c*Range[100]]] (* G. C. Greubel, Mar 27 2018 *)
  • PARI
    for(n=1,100, print1(floor(n*(sqrt(6) + sqrt(2) + 2)/4), ", ")) \\ G. C. Greubel, Mar 27 2018
    

A138281 a(n) = floor((sqrt(2) + sqrt(3))^n).

Original entry on oeis.org

1, 3, 9, 31, 97, 308, 969, 3051, 9601, 30210, 95049, 299052, 940897, 2960313, 9313929, 29304086, 92198401, 290080547, 912670089, 2871501385, 9034502497, 28424933309, 89432354889, 281377831710, 885289046401, 2785353383794, 8763458109129, 27572156006234
Offset: 0

Views

Author

Reinhard Zumkeller, Mar 12 2008

Keywords

Crossrefs

Programs

  • Magma
    [Floor((Sqrt(2) + Sqrt(3))^n): n in [0..50]]; // G. C. Greubel, Jan 27 2018
  • Mathematica
    Table[Floor[(Sqrt[2] + Sqrt[3])^n], {n, 0, 50}] (* G. C. Greubel, Jan 27 2018 *)
  • PARI
    for(n=0,50, print1(floor((sqrt(2) + sqrt(3))^n), ", ")) \\ G. C. Greubel, Jan 27 2018
    

Formula

a(2*n) = floor(A001079(n) + A001078(n)*sqrt(6));
(sqrt(2) + sqrt(3))^(2*n) = A001079(n) + A001078(n)*sqrt(6);
a(2*n+1) = floor(A054320(n)*sqrt(2) + A138288(n)*sqrt(3));
(sqrt(2)+sqrt(3))^(2*n+1) = A054320(n)*sqrt(2) + A138288(n)*sqrt(3).

Extensions

Terms a(16) and a(18) corrected, terms a(19) onward added by G. C. Greubel, Jan 27 2018

A172337 Floor(n*(sqrt(11)+sqrt(7))).

Original entry on oeis.org

0, 5, 11, 17, 23, 29, 35, 41, 47, 53, 59, 65, 71, 77, 83, 89, 95, 101, 107, 113, 119, 125, 131, 137, 143, 149, 155, 160, 166, 172, 178, 184, 190, 196, 202, 208, 214, 220, 226, 232, 238, 244, 250, 256, 262, 268, 274, 280, 286, 292, 298, 304, 310, 316, 321, 327
Offset: 0

Views

Author

Vincenzo Librandi, Feb 01 2010

Keywords

Comments

a(n) = integer part of n*(sqrt(11)+sqrt(7)), where the constant is the largest root of x^4 -36*x^2 +16.

Crossrefs

Programs

  • Magma
    [ Floor(n*(Sqrt(11)+Sqrt(7))): n in [0..60] ];
  • Mathematica
    With[{c = Sqrt[11] + Sqrt[7]}, Floor[c Range[0, 70]]] (* Vincenzo Librandi, Aug 01 2013 *)

A276889 Sums-complement of the Beatty sequence for sqrt(2) + sqrt(3).

Original entry on oeis.org

1, 2, 5, 8, 11, 14, 17, 20, 21, 24, 27, 30, 33, 36, 39, 42, 43, 46, 49, 52, 55, 58, 61, 64, 65, 68, 71, 74, 77, 80, 83, 86, 87, 90, 93, 96, 99, 102, 105, 108, 109, 112, 115, 118, 121, 124, 127, 130, 131, 134, 137, 140, 143, 146, 149, 150, 153, 156, 159, 162
Offset: 1

Views

Author

Clark Kimberling, Oct 01 2016

Keywords

Comments

See A276871 for a definition of sums-complement and guide to related sequences.

Examples

			The Beatty sequence for sqrt(2) + sqrt(3) is A110117 = (0,3,6,9,12,15,18,22,...), with difference sequence s = A276870 = (3,3,3,3,3,3,4,3,3,3,3,3,3,4,3,...).  The sums s(j)+s(j+1)+...+s(k) include (3,4,6,7,9,10,...), with complement (1,2,5,8,11,14,17,20,21,...).
		

Crossrefs

Programs

  • Mathematica
    z = 500; r = Sqrt[2] + Sqrt[3]; b = Table[Floor[k*r], {k, 0, z}]; (* A110117 *)
    t = Differences[b]; (* A276870 *)
    c[k_, n_] := Sum[t[[i]], {i, n, n + k - 1}];
    u[k_] := Union[Table[c[k, n], {n, 1, z - k + 1}]];
    w = Flatten[Table[u[k], {k, 1, z}]]; Complement[Range[Max[w]], w];  (* A276889 *)
Showing 1-10 of 23 results. Next