OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..17858 (first 100000 rows)
EXAMPLE
The table begins:
n n-th row
-- -----------------------
1 1, 2;
2 3, 6;
3 4, 8;
4 5, 10;
5
6 7, 12, 14, 24;
7
8 9, 15, 18, 30;
9
10 11, 22;
11
12 13, 20, 21, 26, 40, 42;
MATHEMATICA
powQ[n_] := n == 2^IntegerExponent[n, 2]; powfQ[n_] := Length[fact = FactorInteger[n]] == 1 && powQ[fact[[1, 2]]];
invIPhi[n_] := Module[{fct = f[n], sol}, sol = Times @@@ (1 + Select[fct, UnsameQ @@ # && AllTrue[# + 1, powfQ] &]); Sort@ Join[sol, 2*sol]]; invIPhi[1] = {1, 2};
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Amiram Eldar, Apr 22 2023
STATUS
approved