506008

Appears in sequences

• a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ... + a(n-3)*a(3) for n >= 4, with initial terms 2, 0, 1, 2.at n=16A025247
• a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ... + a(n-1)*a(1) for n >= 4.at n=16A025265
• Expansion of (1-2x-sqrt(1-4x+4x^2-4x^3))/(2x^2).at n=14A091561
• Number of Dyck paths of semilength n with no peaks at height 0 (mod 3) and no valleys at height 2 (mod 3).at n=15A152225
• Triangle read by rows: T(n,k) is the number of bargraphs of semiperimeter n having k UHU configurations, where U=(0,1), H(1,0); (n>=2, k>=0).at n=56A273896