A215434
Primes of form 2^k + k^2 - 1.
Original entry on oeis.org
2, 7, 31, 1123, 1180591620717411308323, 21778071482940061661655974875633165551139, 89202980794122492566142873090593446023942979, 1569275433846670190958947355801916604025588861116008664323
Offset: 1
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[a: n in [0..250] | IsPrime(a) where a is 2^n+n^2-1];
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Select[Table[2^n + n^2 - 1, {n, 0, 300}], PrimeQ]
A216420
Numbers k such that 13^k + k^13 - 1 is prime.
Original entry on oeis.org
1, 5, 85, 155, 383, 6223
Offset: 1
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[n: n in [0..1000] | IsPrime(13^n+n^13-1)];
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Select[Range[0, 5000], PrimeQ[13^# + #^13 - 1] &]
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is(n)=ispseudoprime(13^n+n^13-1) \\ Charles R Greathouse IV, Jun 13 2017
A216424
Numbers k such that 4^k + k^4 - 1 is prime.
Original entry on oeis.org
2, 16, 74, 164, 518, 796, 8756, 12598
Offset: 1
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[n: n in [0..800] | IsPrime(4^n+n^4-1)];
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Select[Range[0, 5000], PrimeQ[4^# + #^4 - 1] &]
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is(n)=ispseudoprime(4^n+n^4-1) \\ Charles R Greathouse IV, Jun 13 2017
A216592
Numbers m such that 8^m + m^8 + 1 is prime.
Original entry on oeis.org
8^0 + 0^8 + 1 = 2, which is prime, so 0 is in the sequence.
Cf. Numbers m such that k^m + m^k - 1 is prime:
A215439 (k=2),
A215440 (k=3),
A216424 (k=4),
A215443 (k=5),
A216425 (k=6),
A215445 (k=7),
A216591 (k=8),
A216619 (k=10),
A215446 (k=11),
A216420 (k=13),
A216422 (k=19).
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Select[Range[0, 10000], PrimeQ[8^# + #^8 + 1] &]
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is(n)=ispseudoprime(8^n+n^8+1) \\ Charles R Greathouse IV, Jun 13 2017
Showing 1-4 of 4 results.
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