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A246826
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Numbers n such that there is no prime of a prime twin pair between n^2 + n and n^2 + 3*n + 2.
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0
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OFFSET
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1,2
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COMMENTS
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No more values for n = 434 to 45140.
Conjecture: the sequence is finite and given in full.
a(9), if it exists, is greater than 10^5. - Derek Orr, Sep 19 2014
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LINKS
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EXAMPLE
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n = 0 only 1 between 0 and 2 so a(1) = 0.
n = 1 between 2 and 6, 3 is the first of twin pair 3, 5.
For n = 2 to 9 always at least one prime of a twin pair between n^2 + n and n^2 + 3*n + 2.
n = 10 no prime of a twin pair between 110 and 132 so a(2) = 10.
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PROG
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(PARI)
a(n)=forprime(p=n^2+n, n^2+3*n+2, if(precprime(p-1)==p-2||nextprime(p+1)==p+2, return(0))); return(1)
n=0; while(n<10^5, if(a(n), print1(n, ", ")); n++) \\ Derek Orr, Sep 19 2014
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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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