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A174108
Hankel transform of A174107 and A061639(n+1).
2
1, 0, -9, -81, -729, 0, 531441, 43046721, 3486784401, 0, -205891132094649, -150094635296999121, -109418989131512359209, 0, 523347633027360537213511521, 3433683820292512484657849089281
OFFSET
0,3
FORMULA
a(n)=((1/2-sqrt(2)/4)*(cos(3*pi*n/4)+sin(3*pi*n/4))+(1/2+sqrt(2)/4)*(cos(3*pi*n/4)-sin(3*pi*n/4)))*9^floor((n+1)^2/8).
CROSSREFS
Sequence in context: A125910 A171283 A383201 * A254435 A267790 A268014
KEYWORD
easy,sign
AUTHOR
Paul Barry, Mar 07 2010
STATUS
approved