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) u o v, defined by (u o v)(n) = u(v(n));
(2) u o v';
(3) u' o v;
(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.
EXAMPLE
(1) u o v = (3, 6, 9, 10, 14, 15, 16, 19, 23, 24, 26, 28, 30, 33, 36, 37, 41, ...) = A359352
(2) u o v' = (1, 5, 8, 12, 18, 21, 27, 31, 35, 39, 45, 50, 52, 59, 61, 66, 72, ...) = A359353
(3) u' o v = (4, 11, 17, 20, 25, 29, 32, 38, 43, 47, 49, 56, 58, 64, 71, 74, ...) = A360134
(4) u' o v' = (2, 7, 13, 22, 34, 40, 53, 62, 67, 76, 89, 97, 104, 115, 122, ...) = A360135
MATHEMATICA
z = 2000; zz = 100;
u = Accumulate[1 + ThueMorse /@ Range[0, 600]]; (* A026430 *)
u1 = Complement[Range[Max[u]], u]; (* A356133 *)
v = u + 1; (* A285954 *)
v1 = Complement[Range[Max[v]], v]; (* A285953 *)
Table[u[[v[[n]]]], {n, 1, zz}] (* A359352 *)
Table[u[[v1[[n]]]], {n, 1, zz}] (* A359353 *)
Table[u1[[v[[n]]]], {n, 1, zz}] (* A360134 *)
Table[u1[[v1[[n]]]], {n, 1, zz}] (* A360135 *)
PROG
(Python)
def A360134(n): return 3*(m:=n+1+(n-1>>1)+(n-1&1|(n.bit_count()&1^1)))-(2 if (m-1).bit_count()&1 else 1) # Chai Wah Wu, Mar 01 2023
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jan 30 2023
STATUS
approved