a(1) = 1; a(n) = Sum_{k=1..n-1, gcd(n,k) = 1} binomial(n,k)*a(k).
A308475
a(1) = 1; a(n) = Sum_{k=1..n-1, gcd(n,k) = 1} binomial(n,k)*a(k).
Terms
- a(0) =1a(1) =2a(2) =9a(3) =40a(4) =315a(5) =1896a(6) =21651a(7) =191360a(8) =2546487a(9) =28064080a(10) =488517183a(11) =5879603280a(12) =124673371719
External references
- oeis: A308475