a(n) = 27^n * Sum_{k=0..n} binomial(1/3, k)^2.
A367332
a(n) = 27^n * Sum_{k=0..n} binomial(1/3, k)^2.
Terms
- a(0) =1a(1) =30a(2) =819a(3) =22188a(4) =599976a(5) =16212420a(6) =437948784a(7) =11828393820a(8) =319437445365
External references
- oeis: A367332