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 A002256 M0751 N0283 #46 Feb 16 2025 08:32:25 %S A002256 1,2,3,6,7,11,14,17,33,42,43,63,65,67,81,134,162,206,211,366,663,782, %T A002256 1305,1411,1494,2297,2826,3230,3354,3417,3690,4842,5802,6937,7967, %U A002256 9431,13903,22603,24422,39186,43963,47003,49902,67943,114854,127003,145247 %N A002256 Numbers k such that 9*2^k + 1 is prime. %D A002256 H. Riesel, "Prime numbers and computer methods for factorization", Progress in Mathematics, Vol. 57, Birkhauser, Boston, 1985, Chap. 4, see pp. 381-384. %D A002256 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A002256 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A002256 Jeppe Stig Nielsen, <a href="/A002256/b002256.txt">Table of n, a(n) for n = 1..60</a> %H A002256 Ray Ballinger, <a href="http://www.prothsearch.com/index.html">Proth Search Page</a> %H A002256 Ray Ballinger and Wilfrid Keller, <a href="http://www.prothsearch.com/riesel1.html">List of primes k.2^n + 1 for k < 300</a> %H A002256 C. K. Caldwell, <a href="http://www.utm.edu/research/primes/">The Prime Pages</a> %H A002256 Y. Gallot, <a href="http://www.utm.edu/research/primes/programs/gallot/index.html">Proth.exe: Windows Program for Finding Large Primes</a> %H A002256 Wilfrid Keller, <a href="http://www.prothsearch.com/riesel2.html">List of primes k.2^n - 1 for k < 300</a> %H A002256 R. M. Robinson, <a href="https://doi.org/10.1090/S0002-9939-1958-0096614-7">A report on primes of the form k.2^n+1 and on factors of Fermat numbers</a>, Proc. Amer. Math. Soc., 9 (1958), 673-681. %H A002256 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ProthPrime.html">Proth Prime</a> %H A002256 <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> %t A002256 Select[Range[2019],PrimeQ[9*2^#+1]&] (* _Metin Sariyar_, Sep 21 2019 *) %Y A002256 Cf. A050528. %K A002256 nonn %O A002256 1,2 %A A002256 _N. J. A. Sloane_ %E A002256 a(48) from _Arkadiusz Wesolowski_, Oct 22 2011 %E A002256 Added more terms (from http://web.archive.org/web/20161028080239/http://www.prothsearch.net/riesel.html), _Joerg Arndt_, Apr 07 2013 %E A002256 Terms moved from Data to b-file, and more terms put in b-file, by _Jeppe Stig Nielsen_, Sep 21 2019