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 1-9 of 9 results.

A356081 Numbers k such that A356052(k) = A356056(k).

Original entry on oeis.org

1, 3, 4, 6, 8, 14, 16, 17, 22, 25, 27, 28, 30, 38, 40, 67, 68, 74, 78, 82, 102, 104, 109, 110, 112, 126, 128, 132, 136, 140, 160, 164, 188
Offset: 1

Views

Author

Clark Kimberling, Jul 26 2022

Keywords

Comments

Conjectures:
(1) This sequence is finite, with greatest term 188.
(2) The set {A356056(k) - A356052(k)}, for k >=1,
contains every integer >= -5.

Crossrefs

Programs

  • Mathematica
    z = 1000000;
    u = Table[Floor[n (Sqrt[2])], {n, 1, z}];   (* A001951 *)
    u1 = Complement[Range[Max[u]], u];     (* A001952 *)
    v = Table[Floor[n (1/2 + Sqrt[2])], {n, 1, z}]; (* A137803 *)
    v1 = Complement[Range[Max[v]], v];   (* A137804 *)
    t1 = Intersection[u, v];      (* A356052 *)
    t2 = Table[u[[v[[n]]]], {n, 1, z/2}];  (* A356056 *)
    length = Min[Length[t1], Length[t2]]
    t = Take[t2, length] - Take[t1, length];
    {Min[t], Max[t]}
    Flatten[Position[t, 0]]

A346308 Intersection of Beatty sequences for sqrt(2) and sqrt(3).

Original entry on oeis.org

1, 5, 8, 12, 15, 19, 22, 24, 25, 29, 31, 32, 36, 38, 39, 41, 43, 45, 46, 48, 50, 53, 55, 57, 60, 62, 65, 67, 69, 72, 74, 76, 77, 79, 83, 84, 86, 90, 91, 93, 96, 98, 100, 103, 107, 110, 114, 117, 121, 124, 128, 131, 135, 138, 140, 142, 145, 147, 148, 152, 154
Offset: 1

Views

Author

Clark Kimberling, Sep 11 2021

Keywords

Comments

Let d(n) = a(n) - A022840(n). Conjecture: (d(n)) is unbounded below and above, and d(n) = 0 for infinitely many n.
From Clark Kimberling, Jul 26 2022: (Start)
This is the first of four sequences that partition the positive integers. Starting with a general overview, suppose that u = (u(n)) and v = (v(n)) are increasing sequences of positive integers. Let u' and v' be their complements, and assume that the following four sequences are infinite:
(1) u ^ v = intersection of u and v (in increasing order);
(2) u ^ v';
(3) u' ^ v;
(4) u' ^ v'.
Every positive integer is in exactly one of the four sequences. For A346308, u, v, u', v', are the Beatty sequences given by u(n) = floor(n*sqrt(2)) and v(n) = floor(n*sqrt(3)), so that r = sqrt(2), s = sqrt(3), r' = 2 + sqrt(2), s' = (3 + sqrt(3))/2. (See A356052.)
(End)

Examples

			Beatty sequence for sqrt(2): (1,2,4,5,7,8,9,11,12,14,...).
Beatty sequence for sqrt(3): (1,3,5,6,8,10,12,13,15,...).
a(n) = (1,5,8,12,...).
In the notation in Comments:
(1)  u ^ v = (1, 5, 8, 12, 15, 19, 22, 24, 25, 29, 31, 32, ...) =  A346308.
(2)  u ^ v' = (2, 4, 7, 9, 11, 14, 16, 18, 21, 26, 28, 33, 35, ...) =  A356085.
(3)  u' ^ v = (3, 6, 10, 13, 17, 20, 27, 34, 51, 58, 64, 71, 81, ...) = A356086.
(4)  u' ^ v' = (23, 30, 37, 40, 44, 47, 54, 61, 68, 75, 78, 85, ...) = A356087.
		

Crossrefs

Intersection of A001951 and A022838.
Cf. A001952, A022838, A054406, A356085, A356086, A356087, A356088 (composites instead of intersections).

Programs

  • Mathematica
    z = 200;
    r = Sqrt[2]; u = Table[Floor[n*r], {n, 1, z}]  (* A001951 *)
    u1 = Take[Complement[Range[1000], u], z]  (* A001952 *)
    r1 = Sqrt[3]; v = Table[Floor[n*r1], {n, 1, z}]  (* A022838 *)
    v1 = Take[Complement[Range[1000], v], z]  (* A054406 *)
    t1 = Intersection[u, v]    (* A346308 *)
    t2 = Intersection[u, v1]   (* A356085 *)
    t3 = Intersection[u1, v]   (* A356086 *)
    t4 = Intersection[u1, v1]  (* A356087 *)
  • Python
    from math import isqrt
    from itertools import count, islice
    def A346308_gen(): # generator of terms
        return filter(lambda n:n == isqrt(3*(isqrt(n**2//3)+1)**2),(isqrt(n*n<<1) for n in count(1)))
    A346308_list = list(islice(A346308_gen(),30)) # Chai Wah Wu, Aug 06 2022

Formula

In general, if r and s are irrational numbers greater than 1, and a(n) is the n-th term of the intersection (assumed nonempty) of the Beatty sequences for r and s, then a(n) = floor(r*ceiling(a(n)/r)) = floor(s*ceiling(a(n)/s)).

A356056 a(n) = A001951(A137803(n)).

Original entry on oeis.org

1, 4, 7, 9, 12, 15, 18, 21, 24, 26, 29, 31, 33, 36, 39, 42, 45, 48, 50, 53, 56, 59, 62, 63, 66, 69, 72, 74, 77, 80, 83, 86, 89, 91, 93, 96, 98, 101, 104, 107, 110, 113, 115, 118, 121, 124, 125, 128, 131, 134, 137, 140, 142, 145, 148, 151, 154, 156, 158, 161
Offset: 1

Views

Author

Clark Kimberling, Jul 26 2022

Keywords

Comments

This is the first of four sequences that partition the positive integers. Suppose that u = (u(n)) and v = (v(n)) are increasing sequences of positive integers. Let u' and v' be their (increasing) complements, and consider these four sequences:
(1) u o v, defined by (u o v)(n) = u(v(n));
(2) u o v';
(3) u' o v;
(4) u' o v'.
Every positive integer is in exactly one of the four sequences.
Assume that if w is any of the sequences u, v, u', v', then lim_{n->oo} w(n)/n exists and defines the (limiting) density of w. For w = u,v,u',v', denote the densities by r,s,r',s'. Then the densities of sequences (1)-(4) exist, and
1/(r*r') + 1/(r*s') + 1/(s*s') + 1/(s*r') = 1.
For A356056, u, v, u', v', are the Beatty sequences given by u(n) = floor(n*sqrt(2)) and v(n) = floor(n*(1/2 + sqrt(2))), so that r = sqrt(2), s = 1/2 + sqrt(2), r' = 2 + sqrt(2), s' = (9 + 4*sqrt(2))/7.

Examples

			(1)  u o v = (1, 4, 7, 9, 12, 15, 18, 21, 24, 26, 29, 31, ...) = A356056
(2)  u o v' = (2, 5, 8, 11, 14, 16, 19, 22, 25, 28, 32, 35, ...) = A356057
(3)  u' o v = (3, 10, 17, 23, 30, 37, 44, 51, 58, 64, 71, ...) = A356058
(4)  u' o v' = (6, 13, 20, 27, 34, 40, 47, 54, 61, 68, 78, ...) = A356059
		

Crossrefs

Cf. A001951, A001952, A136803, A137804, A356052 (intersections instead of results of composition), A356057, A356058, A356059.

Programs

  • Mathematica
    z = 800;
    u = Table[Floor[n (Sqrt[2])], {n, 1, z}]   (* A001951 *)
    u1 = Complement[Range[Max[u]], u]     (* A001952 *)
    v = Table[Floor[n (1/2 + Sqrt[2])], {n, 1, z}]  (* A137803 *)
    v1 = Complement[Range[Max[v]], v]  (* A137804 *)
    Table[u[[v[[n]]]], {n, 1, z/8}];   (* A356056 *)
    Table[u[[v1[[n]]]], {n, 1, z/8}];  (* A356057 *)
    Table[u1[[v[[n]]]], {n, 1, z/8}];  (* A356058 *)
    Table[u1[[v1[[n]]]], {n, 1, z/8}]; (* A356059 *)

Formula

a(n) = A001951(A137803(n)).

A356057 a(n) = A001951(A137804(n)).

Original entry on oeis.org

2, 5, 8, 11, 14, 16, 19, 22, 25, 28, 32, 35, 38, 41, 43, 46, 49, 52, 55, 57, 60, 65, 67, 70, 73, 76, 79, 82, 84, 87, 90, 94, 97, 100, 103, 106, 108, 111, 114, 117, 120, 123, 127, 130, 132, 135, 138, 141, 144, 147, 149, 152, 155, 159, 162, 165, 168, 171, 173
Offset: 1

Views

Author

Clark Kimberling, Jul 26 2022

Keywords

Comments

This is the second of four sequences that partition the positive integers. See A356056.

Examples

			(1)  u o v = (1, 4, 7, 9, 12, 15, 18, 21, 24, 26, 29, 31, ...) = A356056
(2)  u o v' = (2, 5, 8, 11, 14, 16, 19, 22, 25, 28, 32, 35, ...) = A356057
(3)  u' o v = (3, 10, 17, 23, 30, 37, 44, 51, 58, 64, 71, ...) = A356058
(4)  u' o v' = (6, 13, 20, 27, 34, 40, 47, 54, 61, 68, 78, ...) = A356059
		

Crossrefs

Cf. A001951, A001952, A136803, A137804, A356052 (intersections instead of results of composition), A356056, A356058, A356059.

Programs

  • Mathematica
    u = Table[Floor[n (Sqrt[2])], {n, 1, z}]   (* A001951 *)
    u1 = Complement[Range[Max[u]], u]     (* A001952 *)
    v = Table[Floor[n (1/2 + Sqrt[2])], {n, 1, z}]  (* A137803 *)
    v1 = Complement[Range[Max[v]], v]  (* A137804 *)
    Table[u[[v[[n]]]], {n, 1, z/8}];   (* A356056 *)
    Table[u[[v1[[n]]]], {n, 1, z/8}];  (* A356057 *)
    Table[u1[[v[[n]]]], {n, 1, z/8}];  (* A356058 *)
    Table[u1[[v1[[n]]]], {n, 1, z/8}]; (* A356059 *)

Formula

a(n) = A001951(A137804(n)).

A356058 a(n) = A001952(A137803(n)).

Original entry on oeis.org

3, 10, 17, 23, 30, 37, 44, 51, 58, 64, 71, 75, 81, 88, 95, 102, 109, 116, 122, 129, 136, 143, 150, 153, 160, 167, 174, 180, 187, 194, 201, 208, 215, 221, 225, 232, 238, 245, 252, 259, 266, 273, 279, 286, 293, 300, 303, 310, 317, 324, 331, 338, 344, 351, 358
Offset: 1

Views

Author

Clark Kimberling, Jul 26 2022

Keywords

Comments

This is the third of four sequences that partition the positive integers. See A356056.

Examples

			(1)  u o v   = (1,  4,  7,  9, 12, 15, 18, 21, 24, 26, 29, ...) = A356056
(2)  u o v'  = (2,  5,  8, 11, 14, 16, 19, 22, 25, 28, 32, ...) = A356057
(3)  u' o v  = (3, 10, 17, 23, 30, 37, 44, 51, 58, 64, 71, ...) = A356058
(4)  u' o v' = (6, 13, 20, 27, 34, 40, 47, 54, 61, 68, 78, ...) = A356059
		

Crossrefs

Cf. A001951, A001952, A136803, A137804, A356052 (intersections instead of the results of composition), A356056, A356057, A356059.

Programs

  • Mathematica
    u = Table[Floor[n (Sqrt[2])], {n, 1, z}]   (* A001951 *)
    u1 = Complement[Range[Max[u]], u]     (* A001952 *)
    v = Table[Floor[n (1/2 + Sqrt[2])], {n, 1, z}]  (* A137803 *)
    v1 = Complement[Range[Max[v]], v]  (* A137804 *)
    Table[u[[v[[n]]]], {n, 1, z/8}];   (* A356056 *)
    Table[u[[v1[[n]]]], {n, 1, z/8}];  (* A356057 *)
    Table[u1[[v[[n]]]], {n, 1, z/8}];  (* A356058 *)
    Table[u1[[v1[[n]]]], {n, 1, z/8}]; (* A356059 *)

Formula

a(n) = A001952(A137803(n)).

A356059 a(n) = A001952(A137804(n)).

Original entry on oeis.org

6, 13, 20, 27, 34, 40, 47, 54, 61, 68, 78, 85, 92, 99, 105, 112, 119, 126, 133, 139, 146, 157, 163, 170, 177, 184, 191, 198, 204, 211, 218, 228, 235, 242, 249, 256, 262, 269, 276, 283, 290, 297, 307, 314, 320, 327, 334, 341, 348, 355, 361, 368, 375, 385, 392
Offset: 1

Views

Author

Clark Kimberling, Jul 26 2022

Keywords

Comments

This is the fourth of four sequences that partition the positive integers. See A356056.

Examples

			(1)  u o v = (1, 4, 7, 9, 12, 15, 18, 21, 24, 26, 29, 31, ...) = A356056
(2)  u o v' = (2, 5, 8, 11, 14, 16, 19, 22, 25, 28, 32, 35, ...) = A356057
(3)  u' o v = (3, 10, 17, 23, 30, 37, 44, 51, 58, 64, 71, ...) = A356058
(4)  u' o v' = (6, 13, 20, 27, 34, 40, 47, 54, 61, 68, 78, ...) = A356059
		

Crossrefs

Cf. A001951, A001952, A136803, A137804, A356052 (intersections instead of results of composition), A356056, A356057, A356058.

Programs

  • Mathematica
    u = Table[Floor[n (Sqrt[2])], {n, 1, z}]   (* A001951 *)
    u1 = Complement[Range[Max[u]], u]     (* A001952 *)
    v = Table[Floor[n (1/2 + Sqrt[2])], {n, 1, z}]  (* A137803 *)
    v1 = Complement[Range[Max[v]], v]  (* A137804 *)
    Table[u[[v[[n]]]], {n, 1, z/8}];   (* A356056 *)
    Table[u[[v1[[n]]]], {n, 1, z/8}];  (* A356057 *)
    Table[u1[[v[[n]]]], {n, 1, z/8}];  (* A356058 *)
    Table[u1[[v1[[n]]]], {n, 1, z/8}]; (* A356059 *)

Formula

a(n) = A001952(A137804(n)).

A356053 Intersection of A001951 and A137804.

Original entry on oeis.org

2, 4, 8, 12, 14, 16, 18, 25, 29, 31, 33, 35, 39, 41, 43, 46, 48, 50, 52, 56, 60, 62, 67, 69, 73, 77, 79, 83, 87, 90, 94, 96, 98, 100, 104, 106, 108, 110, 113, 115, 117, 121, 123, 125, 127, 131, 134, 138, 140, 142, 144, 148, 152, 154, 159, 161, 165, 169, 171
Offset: 1

Views

Author

Clark Kimberling, Jul 26 2022

Keywords

Comments

This is the second of four sequences, u^v, u^v', u'^v, u'^v', that partition the positive integers. See A356052.

Examples

			(1)  u ^ v = (1, 5, 7, 9, 11, 15, 19, 21, 22, 24, 26, 28, ...) =  A356052
(2)  u ^ v' = (2, 4, 8, 12, 14, 16, 18, 25, 29, 31, 33, 35, ...) =  A356053
(3)  u' ^ v = (3, 13, 17, 30, 34, 40, 44, 47, 51, 61, 68, ...) = A356054
(4)  u' ^ v' = (6, 10, 20, 23, 27, 37, 54, 58, 64, 71, 75, ...) = A356055
		

Crossrefs

Cf. A001951, A001952, A136803, A137804, A356052, A356054, A356055, A356056 (composites instead of intersections).

Programs

  • Mathematica
    z = 250;
    u = Table[Floor[n (Sqrt[2])], {n, 1, z}]   (* A001951 *)
    u1 = Complement[Range[Max[u]], u]     (* A001952 *)
    v = Table[Floor[n (1/2 + Sqrt[2])], {n, 1, z}]  (* A137803 *)
    v1 = Complement[Range[Max[v]], v]     (* A137804 *)
    Intersection[u, v]    (* A356052 *)
    Intersection[u, v1]   (* A356053 *)
    Intersection[u1, v]   (* A356054 *)
    Intersection[u1, v1]  (* A356055 *)

A356054 Intersection of A001952 and A137803.

Original entry on oeis.org

3, 13, 17, 30, 34, 40, 44, 47, 51, 61, 68, 78, 88, 95, 99, 105, 109, 112, 116, 122, 126, 133, 139, 143, 153, 160, 170, 174, 187, 191, 204, 208, 218, 225, 235, 245, 252, 256, 262, 266, 269, 273, 279, 283, 290, 300, 310, 317, 327, 331, 334, 338, 344, 348
Offset: 1

Views

Author

Clark Kimberling, Jul 26 2022

Keywords

Comments

This is the third of four sequences, u^v, u^v', u'^v, u'^v', that partition the positive integers. See A356052.

Examples

			(1)  u ^ v = (1, 5, 7, 9, 11, 15, 19, 21, 22, 24, 26, 28, ...) =  A356052
(2)  u ^ v' = (2, 4, 8, 12, 14, 16, 18, 25, 29, 31, 33, 35, ...) =  A356053
(3)  u' ^ v = (3, 13, 17, 30, 34, 40, 44, 47, 51, 61, 68, ...) = A356054
(4)  u' ^ v' = (6, 10, 20, 23, 27, 37, 54, 58, 64, 71, 75, ...) = A356055
		

Crossrefs

Cf. A001951, A001952, A136803, A137804, A356052, A356054, A356055, A356056 (composites instead of intersections).

Programs

  • Mathematica
    z = 250;
    u = Table[Floor[n (Sqrt[2])], {n, 1, z}]   (* A001951 *)
    u1 = Complement[Range[Max[u]], u]     (* A001952 *)
    v = Table[Floor[n (1/2 + Sqrt[2])], {n, 1, z}]  (* A137803 *)
    v1 = Complement[Range[Max[v]], v]     (* A137804 *)
    Intersection[u, v]    (* A356052 *)
    Intersection[u, v1]   (* A356053 *)
    Intersection[u1, v]   (* A356054 *)
    Intersection[u1, v1]  (* A356055 *)

A356055 Intersection of A001952 and A137804.

Original entry on oeis.org

6, 10, 20, 23, 27, 37, 54, 58, 64, 71, 75, 81, 85, 92, 102, 119, 129, 136, 146, 150, 157, 163, 167, 177, 180, 184, 194, 198, 201, 211, 215, 221, 228, 232, 238, 242, 249, 259, 276, 286, 293, 297, 303, 307, 314, 320, 324, 341, 351, 355, 358, 368, 372, 378, 385
Offset: 1

Views

Author

Clark Kimberling, Jul 26 2022

Keywords

Comments

This is the fourth of four sequences, u^v, u^v', u'^v, u'^v', that partition the positive integers. See A356052.

Examples

			(1)  u ^ v = (1, 5, 7, 9, 11, 15, 19, 21, 22, 24, 26, 28, ...) =  A356052
(2)  u ^ v' = (2, 4, 8, 12, 14, 16, 18, 25, 29, 31, 33, 35, ...) =  A356053
(3)  u' ^ v = (3, 13, 17, 30, 34, 40, 44, 47, 51, 61, 68, ...) = A356054
(4)  u' ^ v' = (6, 10, 20, 23, 27, 37, 54, 58, 64, 71, 75, ...) = A356055
		

Crossrefs

Cf. A001951, A001952, A136803, A137804, A356052, A356053, A356055, A356056 (composites instead of intersections), A356081.

Programs

  • Mathematica
    z = 250;
    u = Table[Floor[n (Sqrt[2])], {n, 1, z}]   (* A001951 *)
    u1 = Complement[Range[Max[u]], u]     (* A001952 *)
    v = Table[Floor[n (1/2 + Sqrt[2])], {n, 1, z}]  (* A137803 *)
    v1 = Complement[Range[Max[v]], v]     (* A137804 *)
    Intersection[u, v]    (* A356052 *)
    Intersection[u, v1]   (* A356053 *)
    Intersection[u1, v]   (* A356054 *)
    Intersection[u1, v1]  (* A356055 *)
Showing 1-9 of 9 results.