A186035 - OEIS

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A186035

a(n) = (-1)^A186034(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, 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	`Antti Karttunen, Table of n, a(n) for n = 0..4095`
	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(2n+1)+a3(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	`Cf. A001006, A007814, A186034.` `Sequence in context: A122188 A158388 A162285 * A358766 A359154 A359166` `Adjacent sequences: A186032 A186033 A186034 * A186036 A186037 A186038`
	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 26 11:37 EDT 2023. Contains 361549 sequences. (Running on oeis4.)