399360

Appears in sequences

• a(n) = 4^n * n!^2 * Sum_{k=0..n} 1/k!.at n=4A052140
• a(n) = 6*n^2*(2*n + 1).at n=32A190705
• G.f.: Sum_{n>=0} (4*n+1)^n * x^n / (1 + (4*n+1)*x)^n.at n=5A221160
• Decimal representation of the x-axis, from the origin to the right edge, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 353", based on the 5-celled von Neumann neighborhood.at n=18A281288
• Numbers k such that squarefree part of sigma(k) is equal to squarefree part of 2*k.at n=30A331752
• Triangle read by rows: T(n,k) is the number of k-colored graphs on n nodes with restricted labels, n>=0, 0<=k<=n.at n=31A335330