2351805

Appears in sequences

• G.f.: sqrt( (1-x - sqrt(1-14*x+x^2)) / (6*x*(1-14*x+x^2)) ).at n=6A245927
• a(n) = Sum_{k=0..floor(n/3)} (-1)^k * binomial(n,3*k)^2.at n=13A307158
• Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of sqrt(2 / ( (1-2*(k+4)*x+((k-4)*x)^2) * (1+(k-4)*x+sqrt(1-2*(k+4)*x+((k-4)*x)^2)) )).at n=51A337369