|
%I #15 Nov 09 2015 10:14:25
%S 15,33,35,51,65,69,77,85,87,91,95,115,119,123,133,141,143,145,159,161,
%T 177,185,187,209,213,215,217,221,235,247,249,259,265,267,287,295,299,
%U 303,319,321,323,329,335,339,341,365,371,377,391,393,395,403,407,411
%N Semiprimes n (A001358) for which A000001(n) is 1.
%C Semiprimes pq with p<q and gcd(p,q-1)=1. - _T. D. Noe_, Oct 08 2008
%D D. S. Dummit and R. M. Foote, Abstract Algebra, Wiley, 3rd Edition, 2003, page 135.
%H T. D. Noe, <a href="/A142862/b142862.txt">Table of n, a(n) for n=1..1000</a>
%H John H. Conway, Heiko Dietrich and E. A. O'Brien, <a href="http://www.math.auckland.ac.nz/~obrien/research/gnu.pdf">Counting groups: gnus, moas and other exotica</a>.
%t Select[Select[Range[1000],FactorInteger[#][[All, 2]] == {1, 1} &], !
%t Divisible[FactorInteger[#][[2, 1]] - 1, FactorInteger[#][[1, 1]]] &] (* _Geoffrey Critzer_, Nov 07 2015 *)
%Y Cf. A050384, A003277. [_Franklin T. Adams-Watters_, Feb 27 2009]
%K nonn
%O 1,1
%A _N. J. A. Sloane_, Oct 03 2008
%E More terms from _R. J. Mathar_, Oct 04 2008
|
