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A362484
Irregular table read by rows in which the n-th row consists of all the numbers m such that iphi(m) = n, where iphi is the infinitary totient function A091732.
11
1, 2, 3, 6, 4, 8, 5, 10, 7, 12, 14, 24, 9, 15, 18, 30, 11, 22, 13, 20, 21, 26, 40, 42, 16, 32, 17, 27, 34, 54, 19, 28, 38, 56, 33, 66, 23, 46, 25, 35, 36, 39, 50, 60, 70, 72, 78, 120, 29, 58, 31, 44, 48, 62, 88, 96, 45, 51, 90, 102, 37, 52, 57, 74, 84, 104, 114, 168
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};
Table[invIPhi[n], {n, 1, 36}] // Flatten (* using the function f by T. D. Noe at A162247 *)
CROSSREFS
Cf. A091732, A162247, A362485 (row lengths).
Similar sequences: A032447, A361966, A362213, A362180.
Sequence in context: A291604 A082332 A154285 * A258078 A036552 A257987
KEYWORD
nonn,tabf
AUTHOR
Amiram Eldar, Apr 22 2023
STATUS
approved