45658

Appears in sequences

• Number of divisor chains of length n in which the first term is a divisor of n(n+1)/2 ("cyclic" divisor chains).at n=26A094098
• G.f.: [Sum_{n>=0} x^(n*(n+1)/2) * (1+x)^n ]^3.at n=42A182152
• Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with x(i)+x(j), x(i+1)+x(j+1), -(x(i)+x(j+1)), and -(x(i+1)+x(j)) having two or three distinct values for every i<=n and j<=n.at n=11A211461