1Function: istotient
2Section: number_theoretical
3C-Name: istotient
4Prototype: lGD&
5Help: istotient(x,{&N}): true(1) if x = eulerphi(n) for some integer n,
6 false(0) if not. If N is given, set N = n as well.
7Doc: true (1) if $x = \phi(n)$ for some integer $n$, false (0)
8 if not.
9 \bprog
10 ? istotient(14)
11 %1 = 0
12 ? istotient(100)
13 %2 = 0
14 @eprog
15 If $N$ is given, set $N = n$ as well.
16 \bprog
17 ? istotient(4, &n)
18 %1 = 1
19 ? n
20 %2 = 10
21 @eprog
22