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 A102300 Number of distinct prime divisors of n where n and n+1 are composite or twin composite numbers. 0
 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, 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, 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS EXAMPLE For n=8 n+1=9 a twin composite pair. 8=2^3 has 1 distinct divisor, 2. PROG (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) } CROSSREFS Sequence in context: A083534 A174664 A027386 * A202146 A087010 A098220 Adjacent sequences:  A102297 A102298 A102299 * A102301 A102302 A102303 KEYWORD easy,nonn AUTHOR Cino Hilliard, Feb 19 2005 STATUS approved

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Last modified May 21 15:36 EDT 2022. Contains 353921 sequences. (Running on oeis4.)