|
%I #6 Nov 13 2015 11:08:12
%S 1,2,3,4,6,8,9,10,12,14,15,16,18,20,21,22,24,25,26,27,28,30,32,33,34,
%T 35,36,38,39,40,42,44,45,46,48,49,50,51,52,54,55,56,57,58,60,62,63,64,
%U 65,66,68,69,70,72,74,75,76,77,78,80,81,82,84,85,86,87,88,90,91,92,93,94
%N The natural numbers without primes > 3.
%C 1, 2, 3 and the composites A002808.
%t With[{nn=100},Join[{1,2,3},Complement[Range[4,nn],Prime[Range[ PrimePi[ nn]]]]]] (* _Harvey P. Dale_, Nov 18 2013 *)
%o (PARI) is(n)=if(n<5,n>0,!isprime(n)) \\ _Charles R Greathouse IV_, Nov 13 2015
%K nonn,easy,less
%O 1,2
%A _Juri-Stepan Gerasimov_, Dec 12 2009, Dec 15 2009
|
