6016681467domain: NAppears in sequencesa(n) = B(n,n), where B(n,x) = Sum_{k=0..n} Stirling2(n,k)*x^k are the Bell polynomials (also known as exponential polynomials or Touchard polynomials).at n=9A242817E.g.f.: exp(9*(exp(x)-1)).at n=9A276506