cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A096176 Numbers k such that (k^3-1)/(k-1) is prime.

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%I A096176 #27 Sep 08 2022 08:45:14
%S A096176 2,3,5,6,8,12,14,15,17,20,21,24,27,33,38,41,50,54,57,59,62,66,69,71,
%T A096176 75,77,78,80,89,90,99,101,105,110,111,117,119,131,138,141,143,147,150,
%U A096176 153,155,161,162,164,167,168,173,176,188,189,192,194,203,206,209,215,218
%N A096176 Numbers k such that (k^3-1)/(k-1) is prime.
%C A096176 Numbers k > 1 such that k^2 + k + 1 is a prime. - _Vincenzo Librandi_, Nov 16 2010
%C A096176 Therefore essentially the same as A002384. - _Georg Fischer_, Oct 06 2018
%H A096176 Hugo Pfoertner, <a href="/A096176/b096176.txt">Table of n, a(n) for n = 1..10000</a>
%e A096176 a(5) = 8 because (8^3-1)/(8-1) = 511/7 = 73 is prime.
%t A096176 Select[Range[2,550],PrimeQ[(#^3-1)/(#-1)]&] (* _Harvey P. Dale_, Sep 10 2009 *)
%o A096176 (PARI) is(n)=isprime(n^2+n+1) \\ _Charles R Greathouse IV_, Jun 05 2017
%o A096176 (Magma) [n: n in [2..220] |IsPrime((n^3-1) div (n -1))]; // _Vincenzo Librandi_, Oct 07 2018
%Y A096176 Cf. A096174 (n^3+1)/(n+1) is prime, A081257 largest prime factor of n^3-1, A096175 n^3-1 is an odd semiprime.
%Y A096176 Cf. A028491, A004061. - Daniel McCandless (dkmccandless(AT)gmail.com), Aug 31 2009
%Y A096176 Cf. A002384.
%K A096176 nonn
%O A096176 1,1
%A A096176 _Hugo Pfoertner_, Jun 22 2004
%E A096176 3 and 5 added by Daniel McCandless (dkmccandless(AT)gmail.com), Aug 31 2009
%E A096176 Corrected terms, including many previously omitted terms, from _Harvey P. Dale_, Sep 10 2009