%I #4 Oct 01 2013 17:58:07
%S 1,1,2,2,2,2,2,1,2,1,1,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,1,2,2,2,2,2,
%T 2,2,2,1,3,2,2,2,3,2,2,2,2,2,2,2,2,3,3,2,3,2,2,2,2,2,3,1,2,2,2,1,1,2,
%U 3,2,2,2,3,2,2,2,2,2,2,2,2,2,3,2,2,2,2,2,2,3,3,1,3,2,3,2,2,2,3,2,2,2,3,2,2
%N Number of distinct prime divisors of n where n and n+1 are composite or twin composite numbers.
%e For n=8 n+1=9 a twin composite pair. 8=2^3 has 1 distinct divisor, 2.
%o (PARI) f2(n) = for(x=1,n,y=composite(x);if(!isprime(y+1),print1(omega(y)","))) composite(n) =\The n-th composite number. 1 is def as not prime nor composite. { local(c,x); c=1; x=1; while(c <= n, x++; if(!isprime(x),c++); ); return(x) }
%K easy,nonn
%O 1,3
%A _Cino Hilliard_, Feb 19 2005