4680270

Appears in sequences

• Triangular numbers, T(m), that are five-quarters of another triangular number; T(m) such that 4*T(m) = 5*T(k) for some k.at n=3A201004
• a(n) is the smallest hexagonal number for which the symmetric representation of sigma(n) has width 2*n, n >= 0, at the diagonal.at n=10A350712