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A186039
a(n) = (-1)^A186038(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
OFFSET
0
COMMENTS
Hankel transform is A186040.
LINKS
FORMULA
a(n) = (-1)^log_3(A002426(n)/numerator(A002426(n)/3^n)).
MATHEMATICA
Join[{1}, Table[(-1)^(Log[3, GegenbauerC[n, -n, -1/2]/ (Numerator[ GegenbauerC[n, -n, -1/2]/3^n])]), {n, 1, 50}]] (* G. C. Greubel, Mar 06 2017 *)
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Paul Barry, Feb 11 2011
STATUS
approved