A050072 a(n) = |a(n-1) - a(m)| for n >= 4, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = a(3) = 1.

1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0

Offset

1,1

Links

Table of n, a(n) for n=1..90.

Maple

a := proc(n) option remember; `if`(n < 4, 1,
       abs(a(n - 1) - a(Bits:-Iff(n - 2$2) + 3 - n)))
     end:
seq(a(n), n = 1..90); # Petros Hadjicostas, Nov 08 2019

Crossrefs

Sequence in context: A275737 A080909 A087755 * A267576 A156707 A131309

Adjacent sequences: A050069 A050070 A050071 * A050073 A050074 A050075

Keyword

nonn

Author

Clark Kimberling

Extensions

Name edited by Petros Hadjicostas, Nov 08 2019

Status

approved