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A112874
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Numbers n such that the coefficient of x^n in (x^2-x-1)^n is prime.
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0
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3, 4, 5, 6, 7, 10, 11, 12, 26, 160, 3787, 31877
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OFFSET
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1,1
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COMMENTS
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n=31877 yields a probable prime; the others have been proved prime. These n were also found by Eric Weisstein, who found no other n<100000.
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LINKS
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MATHEMATICA
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Select[Range[200], PrimeQ[Coefficient[Expand[(x^2-x-1)^# ], x, # ]]&]
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CROSSREFS
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Cf. A098331 (coefficient of x^n in (x^2-x-1)^n).
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KEYWORD
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hard,nonn
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AUTHOR
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STATUS
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approved
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