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 A064721 #6 Mar 06 2015 23:18:41
%S A064721 383,766,881,1532,1643,1762,2897,3061,3064,3286,3443,3524,3829,4847,
%T A064721 4861,5297,5359,5794,5897,6122,6128,6319,6572,6886,7013,7352,7493,
%U A064721 7651,7658,7909,7957,8119,8269,8423,8543,8929,9323,9694,9722
%N A064721 Potential Sierpiński numbers: integers for which the smallest m > 2^10 in A040076 such that n*2^m+1 is prime (A050921).
%C A064721 The first confirmed Sierpiński number is 78557.
%t A064721 Do[m = 0; While[m <= 2^10 && !PrimeQ[n*2^m + 1], m++ ]; If[m > 2^10, Print[n]], {n, 1, 10^4} ]
%Y A064721 Cf. A040076, A050921.
%K A064721 nonn
%O A064721 1,1
%A A064721 _Robert G. Wilson v_, Oct 16 2001