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 A265497 #23 Sep 08 2022 08:46:14 %S A265497 1,103,190,289,460,483,511,534,651,793,820,880,901,939,945,958,1045, %T A265497 1168,1195,1198,1216,1374,1408,1479,1489,1500,1521,1534,1539,1569, %U A265497 1599,1623,1630,1671,1678,1875,1938,1939,1963,1996,2028,2136,2140,2166,2179,2289 %N A265497 Numbers n such that n*2^127 - 1 is prime. %C A265497 The exponent of 2 in the expression, 127, is a Mersenne exponent. %e A265497 n = 1 is a term since 2^127 - 1 is prime (the 12th Mersenne prime). %t A265497 Select[Range@ 2560, PrimeQ[# 2^127 - 1] &] (* _Michael De Vlieger_, Dec 09 2015 *) %o A265497 (MATLAB) %o A265497 if isprime(n*2^127-1) %o A265497 disp(n) %o A265497 end %o A265497 (PARI) is(n)=ispseudoprime(n*2^127 - 1) \\ _Anders Hellström_, Dec 09 2015 %o A265497 (Magma) [n: n in [1..3*10^3] |IsPrime(n*2^127-1)]; // _Vincenzo Librandi_, Dec 10 2015 %Y A265497 Cf. A000043, A001348, A005122. %K A265497 nonn,easy %O A265497 1,2 %A A265497 _Vardan Semerjyan_, Dec 09 2015