A272597 Numbers n such that the multiplicative group modulo n is the direct product of 7 cyclic groups.

120120, 157080, 175560, 185640, 207480, 212520, 240240, 251160, 267960, 271320, 286440, 291720, 314160, 316680, 326040, 328440, 338520, 341880, 351120, 360360, 367080, 371280, 378840, 394680, 397320, 404040, 408408, 414120, 414960, 425040, 426360, 434280, 442680, 447720, 456456, 462840, 469560, 471240

Offset

1,1

Comments

Numbers n such that A046072(n) = 7.

Links

Table of n, a(n) for n=1..38.

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[5*10^5], A046072[#] == 7&] (* Jean-François Alcover, Dec 22 2021, after Geoffrey Critzer in A046072 *)

Prog

(PARI) for(n=1, 10^6, my(t=#(znstar(n)[2])); if(t==7, print1(n, ", ")));

Crossrefs

Direct product of k groups: A033948 (k=1), A272592 (k=2), A272593 (k=3), A272594 (k=4), A272595 (k=5), A272596 (k=6), A272598 (k=8), A272599 (k=9).

Sequence in context: A234736 A236094 A043622 * A190378 A092015 A250673

Adjacent sequences: A272594 A272595 A272596 * A272598 A272599 A272600

Keyword

nonn

Author

Joerg Arndt, May 05 2016

Status

approved