A186032 a(n) = (-1)^A048881(n).

1, 1, -1, 1, -1, -1, 1, 1, -1, -1, 1, -1, 1, 1, -1, 1, -1, -1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1, -1, -1, 1, 1, -1, -1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1, -1, -1, 1, -1, 1, 1, -1, 1, -1, -1, 1, 1, -1, -1, 1, -1, 1

Offset

0

Comments

Partial sums are A076826(n+1). Hankel transform is A186033.

a(n) = A108784(n+1) for n < 120 and perhaps beyond. Is this (apart from the offset) the same as A108784? - R. J. Mathar, Feb 25 2011

Links

Table of n, a(n) for n=0..60.

Formula

a(n) = (-1)^log_2(A000108(n)/numerator(A000108(n)/2^n)).

Maple

read("transforms") ;
A048881 := proc(n) wt(n+1)-1 ; end proc:
A186032 := proc(n) (-1)^A048881(n) ; end proc: # R. J. Mathar, Feb 25 2011

Prog

(Python 3.10+)
def A186032(n): return 1 if (n+1).bit_count()&1 else -1 # Chai Wah Wu, Nov 15 2022

Crossrefs

Sequence in context: A123271 A121238 A321753 * A212157 A131554 A153881

Adjacent sequences: A186029 A186030 A186031 * A186033 A186034 A186035

Keyword

sign,easy

Author

Paul Barry, Feb 11 2011

Status

approved