404559
domain: N
Appears in sequences
- Numbers k such that sigma(sigma(k)-k) = phi(k).at n=29A074875
- Number of ways to build a contiguous building with n LEGO blocks of size 1 X 8 on top of a fixed block of the same size so that the building is symmetric after a rotation by 180 degrees.at n=5A123815
- Augmentation of the triangle A062344. See Comments.at n=40A193601