1898712domain: NAppears in sequencesa(n) = 2^n - C(n,0) - C(n,1) - ... - C(n,7).at n=21A035040a(n) = Sum_{k=0..13} binomial(n, k).at n=21A219676a(n) = binomial(3*n, n + 1)*hypergeom([1, 1 - 2*n], [2 + n], -1).at n=7A321957