131859

Appears in sequences

• Number of nonempty subsets of {1,2,...,n} in which exactly 4/5 of the elements are <= n/2.at n=26A047168
• Number of nonempty subsets of {1,2,...,n} in which exactly 4/5 of the elements are <= (n-1)/2.at n=26A047179
• Number of ways of placing n nonattacking (normal) queens on n X n board, solutions similar on the torus count only once.at n=14A062165
• Numbers n such that m=(n^2+1)/2, p=(m^2+1)/2 and q=(p^2+1)/2 are all prime.at n=45A188546
• Expansion of (1-sqrt(1-(2*(1-sqrt(1-4*x^2)))/x))/2.at n=12A242566