5044201domain: NAppears in sequencesa(n) = (1 - (-7)^n)/8.at n=8A014989Gaussian binomial coefficient [ n,8 ] for q=-7.at n=1A015363a(n) = 6*a(n-1) + 7*a(n-2), a(0) = 0, a(1) = 1.at n=9A015552