859515920

Appears in sequences

• a(n) = binomial(3*n+1,n)/(n+1).at n=13A006013
• If n = 2*m then a(n) = binomial(3*m, m)/(2*m+1), if n=2*m+1 then a(n) = binomial(3*m+1, m+1)/(2*m+1).at n=27A047749
• a(n) = A047765(2n).at n=26A047767
• Expansion of reversion of (x - 2*x^2) / (1 - x)^3.at n=26A134565
• Number of primitive (1,1) pairs in the Fibonacci tree at depth 3n.at n=13A305574
• a(n) = binomial(A007310(n+1),n+1)/A007310(n+1).at n=13A367521