61720

Appears in sequences

• Integer part of ((4th elementary symmetric function of 1,2,...,n)/(1+2+...+n)).at n=15A024171
• Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 157", based on the 5-celled von Neumann neighborhood.at n=7A270330
• Square array read by antidiagonals downwards: for n >= 2, T(k,n) is the number of permutations of [k+n] that differ in every position from both the identity permutation and a permutation consisting of k 1-cycles and one n-cycle.at n=48A335391
• Expansion of x*(2 - x)/(1 - 5*x + 3*x^2 - x^3).at n=7A361358