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A285888
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Numbers n such that (1 + n)^n + (-n)^n is prime.
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3
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OFFSET
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1,2
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COMMENTS
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The next term, if it exists, is > 10000. - Hugo Pfoertner, Jan 06 2020
The associated primes are: 13, 37, 881, 4651, 1273609, ...
All terms other than 0 are primes or powers of 2.
Heuristically, this sequence might be expected to be finite. (End)
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LINKS
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EXAMPLE
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4 is in this sequence because (1 + 4)^4 + (-4)^4 = 881 is prime.
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MAPLE
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N:= 1000: # to get all terms <= N
cands:= select(isprime, {seq(i, i=3..N, 2)}) union {0, seq(2^k, k=1..ilog2(N))}:
select(n -> isprime((1+n)^n + (-n)^n), cands); # Robert Israel, Apr 28 2017
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PROG
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(Magma) [n: n in [0..170]| IsPrime((n+1)^n + (-n)^n)];
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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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