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A186035 a(n) = (-1)^A186034(n). 3
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, 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 (list; graph; refs; listen; history; text; internal format)
OFFSET
0
COMMENTS
Hankel transform is A186036.
LINKS
FORMULA
a(n) = (-1)^log_2(A001006(n)/numerator(A001006(n)/2^n)).
a(n) = (-1)^A007814(A001006(n)). - Antti Karttunen, Aug 12 2017
PROG
(Python)
from itertools import count, islice
def A186035_gen(): # generator of terms
a, b = 1, 1
yield from (1, 1)
for n in count(2):
a, b = b, (b*(2*n+1)+a*3*(n-1))//(n+2)
yield 1-(((~b&b-1).bit_length()&1)<<1)
A186035_list = list(islice(A186035_gen(), 30)) # Chai Wah Wu, Jul 08 2022
CROSSREFS
Sequence in context: A122188 A158388 A162285 * A358766 A359154 A359166
KEYWORD
sign,easy
AUTHOR
Paul Barry, Feb 11 2011
EXTENSIONS
More terms from Antti Karttunen, Aug 12 2017
STATUS
approved

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Last modified March 29 07:27 EDT 2024. Contains 371265 sequences. (Running on oeis4.)