cp's OEIS Frontend

A268987 Primes of the form k^(k + 1) + k - 1.

%I A268987 #28 Sep 08 2022 08:46:15
%S A268987 83,15629,279941,3486784409,6568408355712890639
%N A268987 Primes of the form k^(k + 1) + k - 1.
%C A268987 The next prime has 171 digits. - _Vincenzo Librandi_, Feb 17 2016
%C A268987 Subsequence of primes of A155499. - _Michel Marcus_, Feb 20 2016
%H A268987 Factordb, <a href="http://factordb.com/index.php?query=n%5E%28n+%2B+1%29+%2B+n+-+1&amp;use=n&amp;n=0&amp;VP=on&amp;VC=on&amp;EV=on&amp;OD=on&amp;PR=on&amp;FF=on&amp;PRP=on&amp;CF=on&amp;U=on&amp;C=on&amp;perpage=200&amp;format=1">n^(n + 1) + n - 1</a>.
%t A268987 Select[Table[n^(n + 1) + n - 1, {n, 1, 50}], ProvablePrimeQ[#] &]
%o A268987 (Magma) [a: n in [0..100] | IsPrime(a) where a is n^(n+1)+n-1]; // _Vincenzo Librandi_, Feb 17 2016
%o A268987 (PARI) lista(nn) = for(k=1, nn, if(ispseudoprime(q=k^(k+1)+k-1), print1(q, ", "))); \\ _Jinyuan Wang_, Mar 01 2020
%Y A268987 Cf. A155499, A161471, A161472, A187602, A187605.
%Y A268987 Cf. A309140 (the corresponding values of k).
%K A268987 nonn
%O A268987 1,1
%A A268987 _Soumadeep Ghosh_, Feb 16 2016