A186039 a(n) = (-1)^A186038(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

Offset

0

Comments

Hankel transform is A186040.

Links

G. C. Greubel, Table of n, a(n) for n = 0..1000

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

Cf. A002426, A186038, A186040.

Sequence in context: A212157 A131554 A160357 * A332433 A376139 A374385

Adjacent sequences: A186036 A186037 A186038 * A186040 A186041 A186042

Keyword

sign,easy

Author

Paul Barry, Feb 11 2011

Status

approved