OFFSET
2,1
COMMENTS
The offset is 2 since cototient(p) = 1 for all primes p.
The 0th row consists of one term, 1, since 1 is the only solution to cototient(x) = 0.
LINKS
Amiram Eldar, Table of n, a(n) for n = 2..9674 (rows 2..1000)
EXAMPLE
The table begins:
n n-th row
-- -----------
2 4;
3 9;
4 6, 8;
5 25;
6 10;
7 15, 49;
8 12, 14, 16;
9 21, 27;
10
11 35, 121;
12 18, 20, 22;
MATHEMATICA
With[{max = 50}, cot = Table[n - EulerPhi[n], {n, 1, max^2}]; row[n_] := Position[cot, n] // Flatten; Table[row[n], {n, 2, max}] // Flatten]
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Amiram Eldar, Apr 11 2023
STATUS
approved