A271718
Numbers n such that n*(n+1)^n - 1 is prime.
Original entry on oeis.org
2, 3, 7, 14, 43, 81, 943, 1621
Offset: 1
14 is a member because 14*15^14 - 1 = 408700964355468749 is a prime number.
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Select[Range[10^3], PrimeQ[# (# + 1)^# - 1] &] (* Michael De Vlieger, Apr 12 2016 *)
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for(n=1,10^10,ispseudoprime(n*(n+1)^n-1)&&print1(n,", "))
A353122
Numbers k such that k^k*(k+1) + 1 is prime.
Original entry on oeis.org
0, 1, 2, 3, 6, 9, 186, 198, 8390
Offset: 1
9 is in the sequence because 9^9*(9+1) + 1 = 3874204891, which is prime.
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[n: n in [0..200] | IsPrime(n^n*(n+1) + 1)];
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Join[{0}, Select[Range[200], PrimeQ[#^#*(# + 1) + 1] &]] (* Amiram Eldar, Apr 25 2022 *)
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isok(k) = ispseudoprime(k^k*(k+1) + 1); \\ Michel Marcus, May 16 2022
Showing 1-2 of 2 results.
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