| Phi(N) |
Robert P. Munafo, 1993 Mar 10.
1. Euler's totient function, the number of integers less than and relatively prime to n. The first 15 terms are: 1, 1, 2, 2, 4, 2, 6, 4, 6, 4, 10, 4, 12, 6, 8, ...
2. The number of secondary continental mu-atoms of period n, or (from period scaling) the number of children of period n f of a given mu-unit whose period is f.