Let $\varphi(n)$ denote the totient function.
For an even positive integer $k$ , define $f(k)$ to be the smallest composite number $n$ satisfying $$\varphi(n+k)-\varphi(n)=k$$ if such a number $n$ exists. For the even numbers upto $44$ , the values are
2 6
4 12
6 21
8 24
10 36
12 45
14 48
16 39
18 63
20 72
22 72
24 95
26 60
28 57
30 224
32 84
34 15
36 135
38 1058
40 45
42 301
44 144
But I do not know whether $f(46)$ exists. If yes , we have $f(46)>10^8$.
Does $f(46)$ exist ? If yes, what is the value ?