84816

Appears in sequences

• Values of n such that (sigma(sigma(n))-phi(phi(n)))/n is an integer (the corresponding integral ratios are given in A136132).at n=29A136131
• Number of directed Hamiltonian paths in the n-Hanoi graph.at n=4A137889
• Number of nX2 0..3 arrays with no more than floor(nX2/2) elements equal to at least one king-move neighbor, with new values introduced in row major 0..3 order.at n=5A222651
• T(n,k)=Number of nXk 0..3 arrays with no more than floor(nXk/2) elements equal to at least one king-move neighbor, with new values introduced in row major 0..3 order.at n=22A222654
• T(n,k)=Number of nXk 0..3 arrays with no more than floor(nXk/2) elements equal to at least one king-move neighbor, with new values introduced in row major 0..3 order.at n=26A222654
• Composite numbers such that product_{i=1..k} (p_i/(p_i-1)) / sum_{i=1..k} (p_i/(p_i-1)) is an integer, where p_i are the k prime factors of n (with multiplicity).at n=20A227034
• a(n) = n*(n + 1)*(17*n - 14)/6.at n=31A237617