A080747 - OEIS

%I #12 Aug 23 2018 02:12:50

%S 561,645,1105,1729,1905,2465,2821,4371,6601,8481,8911,10585,11305,

%T 12801,13741,13981,15841,16705,18705,23001,25761,29341,30121,30889,

%U 33153,34945,39865,41041,41665,46657,52633,55245,57421,62745,63973,68101,72885,74665,75361

%N Sarrus numbers with more than 2 distinct prime factors.

%H Giovanni Resta, <a href="/A080747/b080747.txt">Table of n, a(n) for n = 1..10000</a>

%p for n from 1 to 60000 do if not isprime(n) and modp(2^(n-1),n)=1 and nops(ifactors(n)[2])>2 then printf("%d, ",n) fi od: # C. Ronaldo

%t Select[Range[76000], PowerMod[2, #-1, #] == 1 && PrimeNu[#] > 2 &] (* _Giovanni Resta_, Aug 20 2018 *)

%Y Cf. A001567.

%K nonn

%O 1,1

%A _Benoit Cloitre_, Mar 08 2003

%E Edited by C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 19 2004

%E More terms from _Giovanni Resta_, Aug 20 2018