-53144domain: ZAppears in sequencesa(n) = (1 - (-9)^n)/10.at n=5A014991Triangle of q-binomial coefficients for q=-9.at n=22A015121Triangle of q-binomial coefficients for q=-9.at n=26A015121Gaussian binomial coefficient [ n,5 ] for q = -9.at n=1A015315