2642656

Appears in sequences

• Number of self-inverse permutations p on [n] with displacement of elements restricted by 3: |p(i)-i| <= 3.at n=20A239075
• Greater members of dihedral amicable pairs: numbers (m, k) such that t(m) = t(k) = m + k, where t(k) = sigma(k) + d(k).at n=28A322254