679952

Appears in sequences

• a(n) is the number of equivalence classes of simple, open polygonal chains consisting of two segments and with all three vertices on the lattice points of an n X n grid.at n=33A272053
• Integers x such that there exist four integers 0<y<=z<=t<=w such that sigma(x)^5 = x^5 + y^5 + z^5 + t^5 + w^5.at n=18A386672