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 1-3 of 3 results.

A360405 a(n) = A360393(A356133(n)).

Original entry on oeis.org

2, 6, 15, 27, 34, 45, 55, 60, 69, 81, 91, 96, 108, 114, 124, 135, 142, 153, 163, 168, 180, 186, 195, 208, 217, 222, 231, 244, 249, 262, 271, 276, 285, 297, 307, 312, 324, 330, 339, 352, 361, 366, 375, 387, 394, 405, 414, 421, 432, 438, 447, 459, 466, 477
Offset: 1

Views

Author

Clark Kimberling, Apr 01 2023

Keywords

Comments

This is the fourth 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) v o u, defined by (v o u)(n) = v(u(n));
(2) v' o u;
(3) v o u';
(4) v' o u.
Every positive integer is in exactly one of the four sequences. Their limiting densities are 4/9, 2/9, 2/9, 1/9, respectively (and likewise for A360394-A360401).

Examples

			(1)  v o u = (3, 7, 10, 11, 14, 16, 17, 20, 23, 25, 26, 29, 30, 33, 37, ...) = A360402
(2)  v' o u = (1, 4, 9, 13, 19, 22, 24, 31, 36, 40, 42, 49, 51, 58, 64, ...) = A360403
(3)  v o u' = (5, 8, 12, 18, 21, 28, 32, 35, 39, 46, 50, 53, 59, 62, 67, ...) = A360404
(4)  v' o u' = (2, 6, 15, 27, 34, 45, 55, 60, 69, 81, 91, 96, 108, 114, ...) = A360405

Crossrefs

Cf. A026530, A360392, A360393, A360394-A3546352 (intersections instead of results of compositions), A360398-A360401 (results of reversed compositions), A360402, A360403, A360404.

Programs

  • Mathematica
    z = 2000; zz = 100;
u = Accumulate[1 + ThueMorse /@ Range[0, 600]]; (* A026430 *)
u1 = Complement[Range[Max[u]], u];  (* A356133 *)
v = u + 2;  (* A360392 *)
v1 = Complement[Range[Max[v]], v]; (* A360393 *)
Table[v[[u[[n]]]], {n, 1, zz}]     (* A360402 *)
Table[v1[[u[[n]]]], {n, 1, zz}]    (* A360403 *)
Table[v[[u1[[n]]]], {n, 1, zz}]    (* A360404 *)
Table[v1[[u1[[n]]]], {n, 1, zz}]   (* A360405 *)

A360402 a(n) = A360392(A026430(n)).

Original entry on oeis.org

3, 7, 10, 11, 14, 16, 17, 20, 23, 25, 26, 29, 30, 33, 37, 38, 41, 43, 44, 47, 48, 52, 54, 56, 57, 61, 63, 65, 68, 70, 71, 74, 77, 79, 80, 83, 84, 88, 90, 92, 93, 97, 100, 101, 104, 105, 107, 110, 111, 115, 118, 119, 122, 123, 125, 128, 131, 132, 134, 137
Offset: 1

Views

Author

Clark Kimberling, Mar 11 2023

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) v o u, defined by (v o u)(n) = v(u(n));
(2) v' o u;
(3) v o u';
(4) v' o u.
Every positive integer is in exactly one of the four sequences. Their limiting densities are 4/9, 2/9, 2/9, 1/9, respectively (and likewise for A360394-A360401).

Examples

			(1)  v o u = (3, 7, 10, 11, 14, 16, 17, 20, 23, 25, 26, 29, 30, 33, 37, ...) = A360402
(2)  v' o u = (1, 4, 9, 13, 19, 22, 24, 31, 36, 40, 42, 49, 51, 58, 64, ...) = A360403
(3)  v o u' = (5, 8, 12, 18, 21, 28, 32, 35, 39, 46, 50, 53, 59, 62, 67, ...) = A360404
(4)  v' o u' = (2, 6, 15, 27, 34, 45, 55, 60, 69, 81, 91, 96, 108, 114, ...) = A360405

Links

Crossrefs

Cf. A026530, A360392, A360393, A360394-A3546352 (intersections instead of results of compositions), A360398-A360401 (results of reversed compositions), A360403, A360404, A360405.

Programs

  • Mathematica
    z = 2000; zz = 100;
u = Accumulate[1 + ThueMorse /@ Range[0, 600]]; (* A026430 *)
u1 = Complement[Range[Max[u]], u];  (* A356133 *)
v = u + 2;  (* A360392 *)
v1 = Complement[Range[Max[v]], v];  (* A360393 *)
Table[v[[u[[n]]]], {n, 1, zz}]    (* A360402 *)
Table[v1[[u[[n]]]], {n, 1, zz}]   (* A360403 *)
Table[v[[u1[[n]]]], {n, 1, zz}]   (* A360404 *)
Table[v1[[u1[[n]]]], {n, 1, zz}]  (* A360405 *)
  • Python
    def A360392(n): return n+2+(n-1>>1)+(n-1&1|(n.bit_count()&1^1))
def A026430(n): return n+(n-1>>1)+(n-1&1|(n.bit_count()&1^1))
def A360402(n): return A360392(A026430(n)) # Winston de Greef, Mar 24 2023

A360403 a(n) = A360393(A026430(n)).

Original entry on oeis.org

1, 4, 9, 13, 19, 22, 24, 31, 36, 40, 42, 49, 51, 58, 64, 66, 73, 76, 78, 85, 87, 94, 99, 103, 106, 112, 117, 121, 126, 129, 133, 139, 144, 148, 150, 157, 159, 166, 171, 175, 178, 184, 189, 193, 199, 202, 204, 210, 213, 220, 225, 229, 235, 238, 240, 246, 253
Offset: 1

Views

Author

Clark Kimberling, Mar 11 2023

Keywords

Comments

This is the second 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) v o u, defined by (v o u)(n) = v(u(n));
(2) v' o u;
(3) v o u';
(4) v' o u.
Every positive integer is in exactly one of the four sequences. Their limiting densities are 4/9, 2/9, 2/9, 1/9, respectively (and likewise for A360394-A360401).

Examples

			(1)  v o u = (3, 7, 10, 11, 14, 16, 17, 20, 23, 25, 26, 29, 30, 33, 37, ...) = A360402
(2)  v' o u = (1, 4, 9, 13, 19, 22, 24, 31, 36, 40, 42, 49, 51, 58, 64, ...) = A360403
(3)  v o u' = (5, 8, 12, 18, 21, 28, 32, 35, 39, 46, 50, 53, 59, 62, 67, ...) = A360404
(4)  v' o u' = (2, 6, 15, 27, 34, 45, 55, 60, 69, 81, 91, 96, 108, 114, ...) = A360405

Links

Crossrefs

Cf. A026530, A360392, A360393, A360394-A3546352 (intersections instead of results of compositions), A360398-A360401 (results of reversed compositions), A360402, A360404, A360405.

Programs

  • Mathematica
    z = 2000; zz = 100;
u = Accumulate[1 + ThueMorse /@ Range[0, 600]]; (* A026430 *)
u1 = Complement[Range[Max[u]], u];  (* A356133 *)
v = u + 2;  (* A360392 *)
v1 = Complement[Range[Max[v]], v];  (* A360393 *)
Table[v[[u[[n]]]], {n, 1, zz}]    (* A360402 *)
Table[v1[[u[[n]]]], {n, 1, zz}]   (* A360403 *)
Table[v[[u1[[n]]]], {n, 1, zz}]   (* A360404 *)
Table[v1[[u1[[n]]]], {n, 1, zz}]  (* A360405 *)
  • Python
    def A360393(n):
    if n < 3: return [0, 1, 2][n]
    return 3*n - 5 - (n-3).bit_count() % 2
def A026430(n): return n+(n-1>>1)+(n-1&1|(n.bit_count()&1^1))
def A360403(n): return A360393(A026430(n)) # Winston de Greef, Mar 24 2023
Showing 1-3 of 3 results.

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