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A184821
a(n) = n + floor(n*t) + floor(n/t), where t is the tribonacci constant.
3
2, 6, 9, 13, 16, 20, 22, 26, 29, 33, 36, 40, 43, 46, 50, 53, 57, 60, 63, 66, 70, 73, 77, 81, 83, 87, 90, 94, 97, 101, 104, 107, 110, 114, 118, 121, 125, 127, 131, 134, 138, 141, 145, 147, 151, 155, 158, 162, 165, 168, 171, 175, 178, 182, 185, 189, 191, 195, 199, 202, 206, 209, 212, 215, 219, 222, 226, 229, 232, 236, 239, 243, 246, 250, 252, 256, 259, 263, 266, 270, 273, 276, 280, 283, 287, 290, 294, 296, 300, 303, 307, 311, 314, 317, 320, 324, 327, 331, 334, 337, 340, 344, 347, 351, 355, 357, 361, 364, 368, 371, 375, 378, 381, 384, 388, 392, 395, 399, 401, 405, 408, 412, 415, 419, 421, 425, 429, 432
OFFSET
1,1
COMMENTS
This is one of three sequences that partition the positive integers.
Given t is the tribonacci constant, then the following sequences are disjoint:
. A184820(n) = n + [n/t] + [n/t^2],
. A184821(n) = n + [n*t] + [n/t],
. A184822(n) = n + [n*t] + [n*t^2], where []=floor.
This is a special case of Clark Kimberling's results given in A184812.
FORMULA
Limit a(n)/n = t^2 = 3.3829757679...
a(n) = n + floor(n*p/q) + floor(n*r/q), where p=t, q=t^2, r=t^3, and t is the tribonacci constant (see Clark Kimberling's formula in A184812).
EXAMPLE
Let t be the tribonacci constant, then t^2 = 1 + t + 1/t where:
t = 1.8392867552..., t^2 = 3.3829757679..., t^3 = 6.2222625231...
PROG
(PARI) {a(n)=local(t=real(polroots(1+x+x^2-x^3)[1])); n+floor(n*t)+floor(n/t)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jan 22 2011
STATUS
approved