491040

Appears in sequences

• a(n) = n*(n + 1)*(n + 2)*(n + 3)/2.at n=30A033486
• Even legs of Pythagorean triangles whose other leg and hypotenuse are both prime.at n=31A067755
• Sigma unitary-sigma perfect numbers: numbers m which satisfy the following equation for some integer k: sigma(usigma(m)) = k*m where usigma(m) is sum of unitary divisors of m.at n=32A083288
• a(n) = C(1+n,1) * C(2+n,1) * C(4+n,2).at n=29A112415
• Number of lone-child-avoiding locally disjoint rooted identity trees whose leaves form an integer partition of n.at n=17A316694
• a(n) = (k+1)*n + k*(k+1)/2, where k = A332542(n).at n=29A332544
• Triangle read by rows: T(n,k) is the number of acyclic digraphs on n labeled nodes with k arcs and a global source, n >= 1, k = 0..n*(n-1)/2.at n=35A350487
• Numbers m such that A188999(A034448(m)) = k*m for some k, where A034448 and A188999 are respectively the unitary and the bi-unitary sigma function.at n=44A369205