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.
%I A006599 M1358 #37 Jul 08 2025 16:50:21 %S A006599 0,1,2,5,9,14,78,81,141,189,498,5070,7349,38645,42618,53346 %N A006599 Numbers k such that 2^(2k+1) + 2^(k+1) + 1 is prime. %C A006599 Some of the larger entries may only correspond to probable primes. %C A006599 Next term >= 10^4. - _Jeppe Stig Nielsen_, Mar 28 2014 %D A006599 J. Brillhart et al., Factorizations of b^n +- 1. Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 2nd edition, 1985; and later supplements. %D A006599 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A006599 J. Brillhart et al., <a href="http://dx.doi.org/10.1090/conm/022">Factorizations of b^n +- 1</a>, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002. %H A006599 S. S. Wagstaff, Jr., <a href="http://www.cerias.purdue.edu/homes/ssw/cun/index.html">The Cunningham Project</a> %F A006599 a(n) = A108062(n) - 1. - _Michael S. Branicky_, Jan 02 2025 %o A006599 (PARI) isok(n) = isprime(2^(2*n+1) + 2^(n+1) + 1); \\ _Michel Marcus_, Mar 28 2014 %Y A006599 A108062 is essentially the same sequence. %K A006599 nonn,more %O A006599 1,3 %A A006599 _N. J. A. Sloane_ %E A006599 More terms from _Rick L. Shepherd_, Sep 07 2002 %E A006599 a(13) from _Jeppe Stig Nielsen_, Mar 28 2014 %E A006599 a(14)-a(16) from _Michael S. Branicky_, Jan 02 2025