|
|
A143221
|
|
a(0)=1. For n >=1, a(n) = 0 if the binary representation of n occurs at least once in the concatenation of (a(0),a(1),...,a(n-1)). a(n) = 1 otherwise.
|
|
3
|
|
|
1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,1
|
|
LINKS
|
|
|
EXAMPLE
|
The binary representation of 21 is 10101. This occurs in the concatenation of terms a(0) through a(20) like so: 10010111(10101)00010010. So a(21) = 0.
|
|
MAPLE
|
S:= "1":
for n from 1 to 1000 do
if StringTools:-Search(convert(convert(n, binary), string), S) = 0 then S:= cat(S, "1") else S:= cat(S, "0") fi
od:
map(parse, StringTools:-Explode(S)); # Robert Israel, May 06 2018
|
|
MATHEMATICA
|
f[l_List]:=Append[l, Boole[StringPosition[ToString[FromDigits[l]], ToString[FromDigits[IntegerDigits[Length[l], 2]]]]=={}]]; Nest[f, {1}, 125] (* Ray Chandler, Nov 09 2008 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
base,nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|