201110

Appears in sequences

• The common value of sigma_2 for square-amicable numbers, sigma_2(m)=sigma_2(n), m<n.at n=30A110929
• Number of 5 X n 0..1 arrays with antidiagonals unimodal and rows and diagonals nondecreasing.at n=27A224041
• a(n) = Sum_{m=0..n} 3^v3(m!), where v3(m!) is the exponent of the highest power of 3 dividing n!, expressed in base 3.at n=12A294493
• a(n) = A115004(n) - A334701(n).at n=41A335179