a(n) = (1/(8*n)) * Sum_{d|n} mu(n/d) * binomial(2*d,d)^3.
A029807
a(n) = (1/(8*n)) * Sum_{d|n} mu(n/d) * binomial(2*d,d)^3.
Terms
- a(0) =1a(1) =13a(2) =333a(3) =10712a(4) =400075a(5) =16435017a(6) =721861385a(7) =33308540000
External references
- oeis: A029807