30016

Appears in sequences

• Number of clouds with n points; number of undirected 2-regular labeled graphs; or number of n X n symmetric matrices with (0,1) entries, trace 0 and all row sums 2.at n=9A001205
• Gaps of 8 in sequence A038593 (lower terms).at n=19A038655
• Triangle T(n,k) (n >= 1, 0 <= k <= n-1) giving number of regular labeled graphs with n nodes and degree k, read by rows.at n=38A059441
• Triangle T(n,k) (n >= 1, 0 <= k <= n-1) giving number of regular labeled graphs with n nodes and degree k, read by rows.at n=42A059441
• Numbers k such that the number of steps to reach 1 in '3x+1' problem equals tau(k), the number of divisors of k.at n=36A070980
• Expansion of (1-4x+12x^2-16x^3+8x^4)/(1-x)^5.at n=30A119327
• Triangle read by rows: T(n,k) = number of simple graphs on n labeled nodes with k edges that are node-disjoint unions of undirected cycle subgraphs.at n=54A144161
• Triangle T(n,k), n>=0, 0<=k<=n, read by rows: T(n,k) = number of simple graphs on n labeled nodes with k edges where each maximally connected subgraph is either a tree or a cycle.at n=54A144163
• Triangle by rows T(n,k), showing the number of meanders with length (n+1)*3 and containing (k+1)*3 L's and (n-k)*3 R's, where L's and R's denote arcs of equal length and a central angle of 120 degrees which are positively or negatively oriented.at n=42A194595
• Number T(n,k) of permutations of {1,2,...,n} that result in a binary search tree of height k; triangle T(n,k), n>=0, 0<=k<=n, read by rows.at n=52A195581
• Numbers n such that n^2 is divisible by the sum of the distinct prime divisors of n^2 + 1.at n=17A196219
• Triangular array read by rows: T(n,k) is the number of simple labeled graphs on n nodes with unicyclic components having exactly k nodes with degree 1; n>=3, 0<=k<=n-3.at n=21A217763
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 670", based on the 5-celled von Neumann neighborhood.at n=39A273394
• a(n) is a number of lattice points in 3D Cartesian grid between cube with edge length 2*n centered in origin and its inscribed sphere. Three pairs of the cube's faces are parallel to the planes XOY, XOZ, YOZ respectively.at n=20A303743
• Number of subsets of {2..n} containing the product of any set of distinct elements whose product is <= n.at n=16A308542
• Triangle read by rows: T(n,k) is the number of connected k-regular simple graphs on n labeled vertices, (0 <= k < n).at n=42A324163
• Number of subsets of {1..n} containing the product of any set of distinct elements whose product is <= n.at n=16A326081
• The number of labeled 6-regular graphs on n nodes.at n=9A339847
• Triangle read by rows: T(n,k) is the number of labeled simple graphs with n edges and k vertices and without endpoints or isolated vertices.at n=44A369931
• Number of subsets of {2..n} such that it is not possible to choose a different binary index of each element.at n=16A370643