50071
domain: N
Appears in sequences
- Numbers k such that sigma(phi(k)) - phi(sigma(k)) is nonzero and divisible by sigma(k), that is A065395(k)/A000203(k) is a nonzero integer.at n=35A092588
- Number of (n+2)X(4+2) 0..1 arrays with every 3X3 subblock sum of the two sums of the diagonal and antidiagonal minus the two minimums of the central column and central row nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=28A254903
- Minimum number k such that the k-th tetrahedral number is not smaller than n!.at n=15A308852