login
A360404
a(n) = A360392(A356133(n)).
4
5, 8, 12, 18, 21, 28, 32, 35, 39, 46, 50, 53, 59, 62, 67, 72, 75, 82, 86, 89, 95, 98, 102, 109, 113, 116, 120, 127, 130, 136, 140, 143, 147, 154, 158, 161, 167, 170, 174, 181, 185, 188, 192, 198, 201, 207, 212, 215, 221, 224, 228, 234, 237, 243, 248, 251
OFFSET
1,1
COMMENTS
This is the third 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).
EXAMPLE
(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
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 *)
CROSSREFS
Cf. A026530, A360392, A360393, A360394-A3546352 (intersections instead of results of compositions), A360398-A360401 (results of reversed compositions), A360402, A360403, A360405.
Sequence in context: A325438 A314411 A359353 * A362243 A069102 A001043
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Apr 01 2023
STATUS
approved