43833

Appears in sequences

• Aitken's array: triangle of numbers {a(n,k), n >= 0, 0 <= k <= n} read by rows, defined by a(0,0)=1, a(n,0) = a(n-1,n-1), a(n,k) = a(n,k-1) + a(n-1,k-1).at n=49A011971
• Sequence formed by reading rows of triangle defined in A011971.at n=40A011972
• Number of oriented multigraphs on n labeled arcs (without loops).at n=5A020556
• Triangle of certain generalized Bell numbers.at n=22A090210
• Number of different values assumed by a/b+c/d as a,b,c,d range between 1 and n.at n=24A119868
• Mirror image of the Bell triangle A011971, which is also called the Pierce triangle or Aitken's array.at n=50A123346
• a(n) arises in the normal ordering of n-th power of the operator (d/dx)(x(d/dx))^4.at n=2A157280
• Generalized vertical Bell numbers of order 4.at n=2A182924
• 5th differences of Bell numbers.at n=5A191099
• T(n,k) = Number of n X k nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any horizontal, vertical, diagonal or antidiagonal neighbor (colorings ignoring permutations of colors).at n=22A208021
• T(n,k) = Number of n X k nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any horizontal, vertical, diagonal or antidiagonal neighbor (colorings ignoring permutations of colors).at n=26A208021
• Number of horizontal and antidiagonal neighbor colorings of the odd squares of an n X 2 array with new integer colors introduced in row major order.at n=9A216078
• G.f.: Product_{k>=1} (1+x^k)^(3*k+2).at n=10A255837
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 139", based on the 5-celled von Neumann neighborhood.at n=40A270280