44506domain: NAppears in sequences4-dimensional analog of centered polygonal numbers.at n=20A006322Numbers n such that n*phi(n-1) is a perfect square.at n=24A069069a(n) = Sum_{i+j+k=n, 0<=j<=i<=k<=n} (n+k)!/(i! * j! * (2*k)!).at n=9A092466a(n) = 87*2^n - 38 (n>=0).at n=9A304171