171112

Appears in sequences

• a(n) = Sum_{k=0..floor(n/6)} binomial(n-3k,3k).at n=28A100134
• Expansion of (1 + x)/(1 - x^3*(1 + x)^3).at n=27A375319
• a(n) = Sum_{k=0..floor(n/3)} binomial(2*n-3*k,3*k).at n=14A392402