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A335984
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Numbers m such that more than half the distinct positive terms of the sequence -k^2 + m*k - 1 are primes.
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1
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4, 5, 7, 9, 11, 19, 21, 31, 33, 39, 49, 51, 81, 99, 101, 123, 129, 159, 171, 177, 189, 231, 291, 441, 879, 1011, 2751
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OFFSET
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1,1
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COMMENTS
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Numbers m such that more than half the distinct terms in row m-2 of the triangular array A059036 are prime.
All positive terms of the sequence are prime for m = 1, 2, 4, 5, 9 and 21.
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LINKS
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EXAMPLE
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7 is in the sequence because with g(k) = -k^2+7*k-1, the positive terms of the sequence g(k) are 5=g(1), 9=g(2) and 11=g(3), and two out of the three (5 and 9) are prime.
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MAPLE
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filter:= n -> nops(select(isprime, [seq(n*x-x^2-1, x=1..n/2)])) > 1/2*floor(n/2):
select(filter, [$1..10000]);
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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