a(n) = coefficient of x^n in the (n-1)-th iteration of (x + x^2 + x^3) for n>=1.

A166881

a(n) = coefficient of x^n in the (n-1)-th iteration of (x + x^2 + x^3) for n>=1.

Terms

    a(0) =1a(1) =1a(2) =4a(3) =24a(4) =216a(5) =2540a(6) =36930a(7) =639093a(8) =12821788a(9) =292495896a(10) =7475306400a(11) =211531253076

External references