1124352

Appears in sequences

• Let S(n)=sigma(n)/3. Numbers k such that S(S(k))=k, 1/3-sociable number of order 1 or 2.at n=6A113546
• Largest members of fully k-sociable cycles of order r.at n=30A183023
• Let S(n)=sigma(n)/3. Numbers k such that S^m(k)=k, 1/3-sociable numbers (of any order).at n=23A356548
• a(n) = Sum_{k=0..n} k^6 * (-1)^k * 3^(n-k) * binomial(n,k).at n=12A383155