A272595 - OEIS

A272595

Numbers n such that the multiplicative group modulo n is the direct product of 5 cyclic groups.

840, 1320, 1560, 1680, 1848, 2040, 2184, 2280, 2520, 2640, 2760, 2856, 3080, 3120, 3192, 3360, 3432, 3480, 3640, 3696, 3720, 3864, 3960, 4080, 4200, 4368, 4440, 4488, 4560, 4620, 4680, 4760, 4872, 4920, 5016, 5040, 5160, 5208, 5280, 5304, 5320, 5460, 5520, 5544, 5640, 5712, 5720, 5880, 5928, 6072, 6120

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OFFSET

1,1

COMMENTS

Numbers n such that A046072(n) = 5.

LINKS

Table of n, a(n) for n=1..51.

MATHEMATICA

A046072[n_] := Which[n == 1 || n == 2, 1,

OddQ[n], PrimeNu[n],

EvenQ[n] && !Divisible[n, 4], PrimeNu[n] - 1,

Divisible[n, 4] && !Divisible[n, 8], PrimeNu[n],

Divisible[n, 8], PrimeNu[n] + 1];

Select[Range[10^4], A046072[#] == 5&] (* Jean-François Alcover, Dec 22 2021, after Geoffrey Critzer in A046072 *)

PROG

(PARI) for(n=1, 10^4, my(t=#(znstar(n)[2])); if(t==5, print1(n, ", ")));

CROSSREFS

Direct product of k groups: A033948 (k=1), A272592 (k=2), A272593 (k=3), A272594 (k=4), A272596 (k=6), A272597 (k=7), A272598 (k=8), A272599 (k=9).

Sequence in context: A144770 A068546 A033269 * A179670 A092002 A169827

Adjacent sequences: A272592 A272593 A272594 * A272596 A272597 A272598

KEYWORD

nonn

AUTHOR

Joerg Arndt, May 05 2016

STATUS

approved