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 A064699 #9 Feb 13 2017 13:34:13
%S A064699 1,3,7,17,19,31,47,383,2897,3061,4847,5359,10223
%N A064699 Integers for which the smallest m in A040076 such that n*2^m+1 is prime (A050921) increases.
%C A064699 Where records occur in A040076. A103964 gives the record values.
%t A064699 a = -1; Do[m = 0; While[ !PrimeQ[n*2^m + 1], m++ ]; If[m > a, a = m; Print[n]], {n, 1, 10^3} ]
%Y A064699 Cf. A040076, A050921.
%K A064699 more,nonn
%O A064699 1,2
%A A064699 _Robert G. Wilson v_, Oct 16 2001
%E A064699 Corrected and extended by _T. D. Noe_, Nov 15 2010
%E A064699 a(13) was found by PrimeGrid, added by _Arkadiusz Wesolowski_, Feb 13 2017