52339

Appears in sequences

• Composite numbers whose prime factors contain no digits other than 4 and 7.at n=10A036318
• Number of nonempty subsets of {1,2,...,n} in which exactly 4/5 of the elements are <= (n-1)/2.at n=25A047179
• Number of nonempty subsets of {1,2,...,n} in which exactly 4/5 of the elements are <= (n-2)/2.at n=25A047190
• a(n) = Sum_{k=0..floor(2*n/5)} (k+1) * binomial(k,2*n-5*k).at n=39A392268
• a(n) = Sum_{k=0..floor(3*n/5)} (k+1) * binomial(k,3*n-5*k).at n=26A392311