|
%I #10 Apr 15 2024 03:27:15
%S 3,4,6,150,180,240,270,420,570,1290,1320,2310,2550,2730,3360,3390,
%T 4260,4650,5850,5880,6360,6780,9000,9240,9630,10530,10890,11970,13680,
%U 13830,14010,14550,16230,16650,18060,18120,18540,19140,19380,21600,21840,23370
%N Numbers m such that m^4-1 has no divisors d with 1 < d < m-1.
%C Essentially the same as A070155, since m^4-1=(m-1)(m+1)(1+m^2). - _R. J. Mathar_, Jun 14 2008
%H Amiram Eldar, <a href="/A129293/b129293.txt">Table of n, a(n) for n = 1..10000</a>
%F A129292(a(n)) = #{1, a(n)-1} = 2.
%e {1,5,7,35,37,185,259,1295} is the set of divisors of 6^4-1, therefore 6 is a term, A129292(6) = #{1,3} = 2.
%o (PARI) is(k) = k == 3 || (isprime(k-1) && isprime(k+1) && isprime(k^2+1)); \\ _Amiram Eldar_, Apr 15 2024
%Y Cf. A070155, A129292, A129295, A129297.
%K nonn,changed
%O 1,1
%A _Reinhard Zumkeller_, Apr 09 2007
|
