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 A265504 #31 Sep 08 2022 08:46:14 %S A265504 1,1144,4027,7485,9039,9940,11286,11781,13095,13236,13869,14124,14764, %T A265504 16630,18075,18795,19284,20797,21436,22696,23904,25297,25419,27391, %U A265504 27564,28146,28392,29865,30624,31087,31137,31369,33286,33724,33741,34609,34837,35034,37047,37075,39564,39910,41181 %N A265504 Numbers n such that n*2^2281 - 1 is prime. %C A265504 The exponent of 2 in the expression, 2281, is a Mersenne exponent. %C A265504 All large values of n correspond to pseudoprimes whose primality needs to be verified. %e A265504 n = 1 is a term since 2^2281 - 1 is prime (the 17th Mersenne prime). %t A265504 Select[Range[10^4], PrimeQ[2^2281 # - 1] &] (* _Vincenzo Librandi_, Jan 12 2016 *) %o A265504 (MATLAB) %o A265504 if isprime(n*2^2281-1) %o A265504 disp(n) %o A265504 end %o A265504 (PARI) is(n)=ispseudoprime(n*2^2281 - 1) \\ _Anders Hellström_, Dec 16 2015 %o A265504 (Magma) [n: n in [1..10^4] |IsPrime(n*2^2281-1)]; // _Vincenzo Librandi_, Jan 12 2016 %Y A265504 Cf. A000043, A001348, A005122. %K A265504 nonn %O A265504 1,2 %A A265504 _Vardan Semerjyan_, Dec 09 2015 %E A265504 More terms from _Soumadeep Ghosh_, Feb 14 2016