67680

Appears in sequences

• a(n) = Sum_{k=0..n} binomial(n, floor(k/2))*3^(n-k).at n=9A127359
• A triangular sequence of four back recursive polynomial that are Hermite H(x,n) like and alternating orthogonal on domain {-Infinity,Infinity} and weight function Exp[ -x^2/2]: P(x, n) = 2*x*P(x, n - 1) - n*P(x, n - 2) + 4*x^3*P(x, n - 3)-n^2*P(x, n - 4).at n=61A138092
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 1), (-1, 1, -1), (1, -1, -1), (1, 0, 0)}.at n=13A148010