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 A001775 M2506 N0991 #38 Nov 06 2023 14:54:35 %S A001775 1,3,5,21,41,49,89,133,141,165,189,293,305,395,651,665,771,801,923, %T A001775 953,3689,5315,6989,15641,48819,78389,134053,167843,181395,311091, %U A001775 353661,645555,916763 %N A001775 Numbers k such that 19*2^k - 1 is prime. %D A001775 H. Riesel, "Prime numbers and computer methods for factorization", Progress in Mathematics, Vol. 57, Birkhäuser, Boston, 1985, Chap. 4, see pp. 381-384. %D A001775 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A001775 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %D A001775 H. C. Williams and C. R. Zarnke, Math. Comp., 22 (1968), 420-422. %H A001775 Wilfrid Keller, <a href="http://www.prothsearch.com/riesel2.html">List of primes k.2^n - 1 for k < 300</a> %H A001775 Kosmaj, <a href="http://www.15k.org/riesellist.html">Riesel list k<300</a>. %H A001775 H. C. Williams and C. R. Zarnke, <a href="http://dx.doi.org/10.1090/S0025-5718-1968-0227095-2">A report on prime numbers of the forms M = (6a+1)*2^(2m-1)-1 and (6a-1)*2^(2m)-1</a>, Math. Comp., 22 (1968), 420-422. %H A001775 <a href="/index/Pri#riesel">Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime</a> %o A001775 (PARI) is(n)=ispseudoprime(19*2^n-1) \\ _Charles R Greathouse IV_, Feb 17 2017 %Y A001775 Cf. A032359 (19*2^k+1 is prime). %K A001775 nonn,hard,more %O A001775 1,2 %A A001775 _N. J. A. Sloane_ %E A001775 More terms from _Hugo Pfoertner_, Jun 22 2004 %E A001775 More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008 %E A001775 Minor corrections by _Charles R Greathouse IV_, Aug 29 2010