51455
domain: N
Appears in sequences
- Numbers k such that phi(k) and sigma(k) are both perfect squares.at n=21A067781
- Number of 5-cycles in the n-polygon diagonal intersection graph.at n=38A300553
- Numbers n such that phi(n), psi(n) and sigma(n) are simultaneously perfect squares.at n=9A301867
- a(n) = 5*(3*n+1)*(9*n+8)/2 (n>=0).at n=27A304508