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.

A277725 Intersection of A158919 and A277723.

Original entry on oeis.org

0, 12, 18, 31, 49, 62, 68, 80, 93, 99, 112, 130, 136, 143, 161, 174, 180, 211, 217, 224, 242, 248, 255, 261, 286, 292, 323, 329, 336, 342, 354, 360, 367, 373, 404, 410, 423, 435, 441, 448, 454, 472, 485, 491, 516, 522, 535, 553, 560, 566, 572, 584, 597, 603, 616, 634, 640, 647, 665, 678, 684, 709, 715
Offset: 1

Views

Author

N. J. A. Sloane, Oct 30 2016

Keywords

Comments

See A277728 for discussion.

Crossrefs

A277726 Intersection of A277722 and A277723.

Original entry on oeis.org

0, 6, 37, 43, 74, 87, 118, 155, 186, 192, 199, 230, 236, 267, 280, 304, 311, 317, 348, 385, 392, 416, 429, 460, 466, 497, 504, 510, 541, 578, 622, 659, 690, 696, 703, 734, 740, 771, 784, 808, 815, 852, 889, 896, 920, 933, 964, 970, 1001, 1008, 1014, 1045, 1082, 1126, 1163, 1194, 1200, 1207, 1238, 1244, 1275, 1288, 1312, 1319, 1356, 1387, 1393, 1400, 1424
Offset: 1

Views

Author

N. J. A. Sloane, Oct 30 2016

Keywords

Comments

See A277728 for discussion.

Crossrefs

Programs

  • Maple
    Digits := 120;
    isA277722 := proc(n)
        a276800 :=  3.3829757679062374941227085364550345869493820437485761820195626772353718960099402922235933340043661396041006 ;
        for x from floor((n-3)/a276800) to (n+3)/a276800 do
            if floor(x*a276800) = n then
                return true;
            end if;
        end do:
        return false;
    end proc:
    isA277723 := proc(n)
        a276801 :=  6.2222625231203986266745611011083211873735607898461684287983213166395751180919067179620287534326731537460804;
        for x from floor((n-3)/a276801) to (n+3)/a276801 do
            if floor(x*a276801) = n then
                return true;
            end if;
        end do:
        return false;
    end proc:
    isA277726 := proc(n)
        isA277722(n) and isA277723(n) ;
    end proc:
    for n from 0 to 8000 do
        if isA277726(n) then
            printf("%d,",n) ;
        end if;
    end do: # R. J. Mathar, Nov 02 2016

Extensions

Corrected by R. J. Mathar, Nov 01 2016

A277727 Union of A158919, A277722, A277723.

Original entry on oeis.org

0, 1, 3, 5, 6, 7, 9, 10, 11, 12, 13, 14, 16, 18, 20, 22, 23, 24, 25, 27, 29, 30, 31, 33, 34, 36, 37, 38, 40, 42, 43, 44, 45, 47, 49, 50, 51, 53, 54, 55, 56, 57, 58, 60, 62, 64, 66, 67, 68, 69, 71, 73, 74, 75, 77, 79, 80, 81, 82, 84, 86, 87, 88, 90, 91, 93, 94, 95, 97, 98, 99, 101, 103, 104, 105, 106
Offset: 1

Views

Author

N. J. A. Sloane, Oct 30 2016

Keywords

Comments

See A277728 for discussion.

Crossrefs

A277728 Numbers not in any of A158919, A277722, A277723.

Original entry on oeis.org

2, 4, 8, 15, 17, 19, 21, 26, 28, 32, 35, 39, 41, 46, 48, 52, 59, 61, 63, 65, 70, 72, 76, 78, 83, 85, 89, 92, 96, 100, 102, 107, 109, 113, 116, 120, 122, 127, 129, 133, 140, 144, 146, 151, 153, 157, 159, 164, 166, 170, 173, 177, 181, 184, 188, 190, 195, 197, 201, 203, 208, 210, 212, 214, 221
Offset: 1

Views

Author

N. J. A. Sloane, Oct 30 2016

Keywords

Comments

Let tau be the tribonacci constant (A058265). Although 1/tau + 1/tau^2 + 1/tau^3 = 1, by Uspensky's 1927 theorem, the three sequences floor(n*tau) (A158919), floor(n*tau^2) (A277722), and floor(n*tau^3) (A277723) cannot form a partition of the nonnegative integers. (Compare Beatty's theorem.)
Entries A277724-A277727 investigate how these three sequences meet, and the present sequence gives the numbers not in any of the three sequences. Any two of the three sequences have a nontrivial intersection, while the intersection of all three is {0}.
On the other hand, the three sequences A003144, A003145, A003146, which arise from the tribonacci word, DO form a partition of the positive integers and are closely connected with the three sequences mentioned in the definition.
It would be nice to have b-files for all the sequences mentioned here. (Many do, but some do not.)

Crossrefs

Programs

  • Mathematica
    maxTerm = 10000;
    a19[n_] := Floor[n*Root[#^3 - #^2 - # - 1&, 1]];
    a22[n_] := Floor[n*Root[#^3 - 3 #^2 - # - 1&, 1]];
    a23[n_] := Floor[n*Root[#^3 - 7 #^2 + 5 # - 1&, 1]];
    A19 = Reap[k = 1; While[a19[k] <= maxTerm, Sow[a19[k++]]]][[2, 1]];
    A22 = Reap[k = 1; While[a22[k] <= maxTerm, Sow[a22[k++]]]][[2, 1]];
    A23 = Reap[k = 1; While[a23[k] <= maxTerm, Sow[a23[k++]]]][[2, 1]];
    Select[Range[maxTerm], FreeQ[A19, #] && FreeQ[A22, #] && FreeQ[A23, #]&] (* Jean-François Alcover, Dec 06 2018 *)

A158919 Beatty sequence for the tribonacci constant tau (A058265): a(n) = floor(n*tau).

Original entry on oeis.org

0, 1, 3, 5, 7, 9, 11, 12, 14, 16, 18, 20, 22, 23, 25, 27, 29, 31, 33, 34, 36, 38, 40, 42, 44, 45, 47, 49, 51, 53, 55, 57, 58, 60, 62, 64, 66, 68, 69, 71, 73, 75, 77, 79, 80, 82, 84, 86, 88, 90, 91, 93, 95, 97, 99, 101, 103, 104, 106, 108, 110
Offset: 0

Views

Author

Eric Culver (weux082690(AT)yahoo.com), Mar 30 2009

Keywords

Comments

Also called the spectrum of tau. Note that A276384 agrees with this sequence for n <= 17160 but disagrees beyond that point. In fact a(17161) = 31564, whereas A276384(17161) = 31563. - N. J. A. Sloane, Sep 03 2016

Examples

			a(3) = floor(3*q) = floor(3*1.8392867...) = floor(5.51786...) = 5.
		

Crossrefs

Cf. A058265, A140099 (spectrum of 1+tau), A276384, A277722, A277723.

Programs

  • Magma
    [Floor(n * (1/3 + 1/3 * (19 - 3 * Sqrt(33))^(1/3) + 1/3 * (19 + 3 * Sqrt(33))^(1/3))) : n in [0..80]]; // Vincenzo Librandi, Oct 28 2018
  • Maple
    x := (1/3)*(1+(19+3*sqrt(33))^(1/3)+(19-3*sqrt(33))^(1/3)) ;
    [seq(floor(n*x),n=0..200)]; # R. J. Mathar, Sep 11 2011
  • Mathematica
    a[n_] := Floor[n Root[#^3 - #^2 - # - 1&, 1]];
    Table[a[n], {n, 0, 100}] (* Jean-François Alcover, Oct 28 2018 *)

Formula

a(n) = floor(n*A058265).

A277722 a(n) = floor(n*tau^2) where tau is the tribonacci constant (A058265).

Original entry on oeis.org

0, 3, 6, 10, 13, 16, 20, 23, 27, 30, 33, 37, 40, 43, 47, 50, 54, 57, 60, 64, 67, 71, 74, 77, 81, 84, 87, 91, 94, 98, 101, 104, 108, 111, 115, 118, 121, 125, 128, 131, 135, 138, 142, 145, 148, 152, 155, 158, 162, 165, 169, 172, 175, 179, 182, 186, 189, 192, 196, 199, 202, 206, 209, 213, 216, 219
Offset: 0

Views

Author

N. J. A. Sloane, Oct 30 2016

Keywords

Crossrefs

Programs

  • Maple
    A277722 := proc(n)
        a276800 :=  3.3829757679062374941227085364550345869493820437485761820195626772353718960099402922235933340043661396041006 ;
        floor(n*a276800) ;
    end proc:
    seq(A277722(n),n=0..100) ; # R. J. Mathar, Nov 02 2016
  • Mathematica
    A277722[n_] := Floor[n (1/3 (1 + (19 - 3 Sqrt[33])^(1/3) + (19 + 3 Sqrt[33])^(1/3)))^2]; Array[A277722, 66, 0] (* JungHwan Min, Nov 06 2016 *)

A277724 Intersection of A158919 and A277722.

Original entry on oeis.org

0, 3, 16, 20, 23, 27, 33, 40, 47, 57, 60, 64, 71, 77, 84, 91, 101, 104, 108, 115, 121, 125, 128, 145, 148, 152, 158, 165, 169, 172, 182, 189, 196, 202, 206, 209, 213, 226, 233, 240, 246, 250, 253, 257, 263, 270, 274, 277, 290, 294, 297, 301, 307, 314, 321, 331, 334, 338, 345, 351, 358, 375, 378, 382
Offset: 1

Views

Author

N. J. A. Sloane, Oct 30 2016

Keywords

Comments

See A277728 for discussion.

Crossrefs

Showing 1-7 of 7 results.