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 A007671 M2481 #28 Jul 21 2024 21:50:29 %S A007671 1,3,5,11,19,29,157,163,283,379,997,10141,14699,77291,85237,106693, %T A007671 203789,3704053 %N A007671 Numbers n such that 2^n + 2^((n + 1)/2) + 1 is prime. %D A007671 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 A007671 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A007671 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 A007671 S. S. Wagstaff, Jr., <a href="http://www.cerias.purdue.edu/homes/ssw/cun/index.html">The Cunningham Project</a> %o A007671 (PARI) for(n=1, 2000, if(n%2==1&&ispseudoprime(2^n+2^((n+1)/2)+1), print1(n,","))) \\ _Charles R Greathouse IV_, Feb 17 2017 edited by _Aurelien Gibier_ Jun 29 2024. %Y A007671 Cf. A057429. %K A007671 nonn,hard,more %O A007671 1,2 %A A007671 _N. J. A. Sloane_, _Robert G. Wilson v_ %E A007671 More terms from _Robert G. Wilson v_, Sep 07 2000 %E A007671 203789 found and proved prime by _Mike Oakes_, on Sep 28 2000. %E A007671 a(18) from _Serge Batalov_, Jun 16 2020