OFFSET
1,1
COMMENTS
Suggested by Leroy Quet, Jul 18 2004.
Note that this is not A137843(n) mod 2. The first difference is at n=14, where a(14) = 0, while A137843(14) = 5. - Antti Karttunen, Aug 31 2017
EXAMPLE
Let s(0) = {1}. Then
s(1) = s(0) U {0} U s(0) = {1,0,1}, since s(0)(1) = 1,
s(2) = s(2) U s(2) = {1,0,1,1,0,1}, since s(1)(2) = 0,
s(3) = s(2) U {0} U s(2) ={1,0,1,1,0,1,0,1,0,1,1,0,1}, since s(2)(3) = 1.
From Antti Karttunen, Aug 31 2017: (Start)
And since s(3)(4) = a(4) = 1, s(4) = s(3) U {0} s(3) = {1,0,1,1,0,1,0,1,0,1,1,0,1,0,1,0,1,1,0,1,0,1,0,1,1,0,1},
Note that because each stage is a prefix of the next (starts with the same terms), we may as well write a(n) instead of s(n-1)(n).
(End)
CROSSREFS
KEYWORD
nonn
AUTHOR
John W. Layman, Jul 20 2004
STATUS
approved