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A186032
a(n) = (-1)^A048881(n).
2
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
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
KEYWORD
sign,easy
AUTHOR
Paul Barry, Feb 11 2011
STATUS
approved