login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A284895
Positions of 1 in A284893; complement of A284894.
4
2, 4, 5, 6, 8, 10, 11, 12, 14, 15, 16, 18, 19, 20, 22, 24, 25, 26, 28, 30, 31, 32, 34, 35, 36, 38, 39, 40, 42, 44, 45, 46, 48, 49, 50, 52, 53, 54, 56, 58, 59, 60, 62, 63, 64, 66, 67, 68, 70, 72, 73, 74, 76, 78, 79, 80, 82, 83, 84, 86, 87, 88, 90, 92, 93, 94
OFFSET
1,1
COMMENTS
Conjecture: 0 < a(n) - n*sqrt(2) < 1 for n >= 1.
The conjecture is false, since a(2) - 2*sqrt(2) = 4-2.828... > 1.17. Presumably the new conjecture is 0 < a(n) - n*sqrt(2) < 2 for n >= 1. - Michel Dekking, Jan 16 2018
This type of behavior typically occurs for Beatty sequences. However, {a(n)} is not a Beatty sequence, since the sequence of first differences {d(n)} of {a(n)} is not Sturmian: in d = 2,1,1,2,2,1,2,1,... there occur 5 words of length 3. One has d = A298231. - Michel Dekking, Jan 16 2018
LINKS
EXAMPLE
As a word, A284893 = 010111010..., in which 0 is in positions 1,3,7,9,...
MATHEMATICA
s = Nest[Flatten[# /. {0 -> {0, 1}, 1 -> {0, 1, 1, 1}}] &, {0}, 6] (* A284893 *)
Flatten[Position[s, 0]] (* A284894 *)
Flatten[Position[s, 1]] (* A284895 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Apr 16 2017
STATUS
approved