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 A281483 #22 Feb 23 2017 22:56:01 %S A281483 1,13,19,29,37,45,51,61,63,65,69,117,171,181,199,201,217,221,265,337, %T A281483 627,631,881,1035,1507,1525,1627,1641,2037,3175,4639,6445,21537,29801, %U A281483 30521,30917,37877,49725,50877,57537,61337,118141,125169,200961,204117,283445,395125,829489 %N A281483 Numbers k such that 32771*2^k + 1 is prime. %C A281483 a(48) = 829489, 1438879 is such that 32771*2^1438879 + 1 is prime with 433151 digits, 829489 < a(49) <= 1438879. %t A281483 Select[Range@ 3000, PrimeQ[32771*2^# + 1] &] (* _Michael De Vlieger_, Jan 23 2017 *) %o A281483 (PFGW) 32771*2^$a+1 %o A281483 $a: from 1 to 1000001 step 2 %o A281483 (PARI) list(limit)=my(i=1); while(i<limit, if(isprime(32771*2^i+1),print1(i, ", ")); i++) \\ _Anders Hellström_, Feb 04 2017 %Y A281483 Cf. A002253. %K A281483 nonn %O A281483 1,2 %A A281483 _Pierre CAMI_, Jan 22 2017