login
Products of 3 distinct not safe primes.
2

%I #2 Mar 31 2012 12:38:20

%S 78,102,114,174,186,222,246,258,318,366,402,426,438,442,474,494,534,

%T 582,606,618,646,654,663,678,741,754,762,786,806,822,834,894,906,942,

%U 962,969,978,986,1038,1054,1066,1086,1102,1118,1131,1146,1158,1178,1182

%N Products of 3 distinct not safe primes.

%C 78=2*3*13; 2,3 and 13 are not safe prime numbers,...

%t lst={};Do[If[Plus@@Last/@FactorInteger[n]==3,a=Length[First/@FactorInteger[n]];If[a==3,b=First/@FactorInteger[n];c=b[[1]];d=b[[2]];e=b[[3]];If[ !PrimeQ[(c-1)/2]&&!PrimeQ[(d-1)/2]&&!PrimeQ[(e-1)/2],AppendTo[lst,n]]]],{n,7!}];lst

%Y Cf. A001358, A005384, A005385, A006881, A007304, A111206, A157342, A157344, A157345, A157346, A157347, A157352, A157353, A157354

%K nonn

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, Feb 27 2009