a(n) = (1/(5*n)) * Sum_{d|n} mu(n/d) * binomial(5*d,d).
A346579
a(n) = (1/(5*n)) * Sum_{d|n} mu(n/d) * binomial(5*d,d).
Terms
- a(0) =1a(1) =4a(2) =30a(3) =240a(4) =2125a(5) =19776a(6) =192129a(7) =1922496a(8) =19692504a(9) =205444500a(10) =2175519379a(11) =23322637440a(12) =252631900235
External references
- oeis: A346579