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A280009
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Orders of consecutive clusters of Chen primes.
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2
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13, 3, 2, 2, 1, 8, 1, 1, 3, 3, 1, 2, 4, 1, 3, 1, 2, 2, 1, 1, 3, 1, 2, 1, 8, 1, 6, 1, 1, 2, 3, 2, 1, 1, 2, 2, 5, 3, 1, 3, 1, 2, 4, 4, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 3, 1, 1, 2, 5, 1, 3, 3, 1, 1
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OFFSET
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1,1
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LINKS
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MATHEMATICA
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Length /@ DeleteCases[Split@ Table[Boole@ And[# != 1, PrimeOmega@ # <= 2] &[# + 2] &@ Prime@ n, {n, 300}], k_ /; Total@ k == 0] (* Michael De Vlieger, Feb 27 2017 *)
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PROG
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(PARI) do(lim)=my(v=List(), u=v, r, s=1); forprime(p=2, lim\2, forprime(q=2, min(lim\p, p), listput(u, p*q))); u=Set(u); r=3; forprime(p=5, lim, if(p-r==2 || setsearch(u, r+2), s++, if(s, listput(v, s); s=0)); r=p); u=0; Vec(v) \\ Charles R Greathouse IV, Feb 27 2017
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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