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A186035 a(n) = (-1)^A186034(n). 3

%I #12 Jul 08 2022 18:01:43

%S 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,

%T 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,

%U 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

%N a(n) = (-1)^A186034(n).

%C Hankel transform is A186036.

%H Antti Karttunen, <a href="/A186035/b186035.txt">Table of n, a(n) for n = 0..4095</a>

%F a(n) = (-1)^log_2(A001006(n)/numerator(A001006(n)/2^n)).

%F a(n) = (-1)^A007814(A001006(n)). - _Antti Karttunen_, Aug 12 2017

%o (Python)

%o from itertools import count, islice

%o def A186035_gen(): # generator of terms

%o a, b = 1, 1

%o yield from (1, 1)

%o for n in count(2):

%o a, b = b, (b*(2*n+1)+a*3*(n-1))//(n+2)

%o yield 1-(((~b&b-1).bit_length()&1)<<1)

%o A186035_list = list(islice(A186035_gen(),30)) # _Chai Wah Wu_, Jul 08 2022

%Y Cf. A001006, A007814, A186034.

%K sign,easy

%O 0

%A _Paul Barry_, Feb 11 2011

%E More terms from _Antti Karttunen_, Aug 12 2017

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Last modified May 8 19:26 EDT 2024. Contains 372341 sequences. (Running on oeis4.)