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 A103964 #17 Jul 17 2019 07:29:25
%S A103964 0,1,2,3,6,8,583,6393,9715,33288,3321063,5054502,31172165
%N A103964 Record values in A040076.
%C A103964 The index sequence of this sequence is 1, 3, 7, 17, 19, 31, 47, 383, 2897. A040076(2897)>8192, not yet found.
%C A103964 A064699 gives where the records occur.
%e A103964 A040076(1)=0, so a(1)=0;
%e A103964 A040076(3)=1, so a(2)=1;
%t A103964 k = -1; n = 0; km = k; While[k < 8192, n++; k = 0; cp = n*(2^ k) + 1; While[(! PrimeQ[cp]) && (k < 8192), k++; cp = n*(2^k) + 1]; If[k > km, km = k; Print[{n, km}]]]
%Y A103964 Cf. A040076, A103963.
%K A103964 nonn,more
%O A103964 1,3
%A A103964 _Lei Zhou_, Feb 24 2005
%E A103964 Extended by _T. D. Noe_, Nov 15 2010
%E A103964 a(13) was found by PrimeGrid, added by _Richard N. Smith_, Jul 15 2019