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 A194637 #18 Apr 03 2023 10:36:12
%S A194637 0,1,2,4,5,6,11,18,20,28,70,106,150,726,2906,7431,14073,22394,41422,
%T A194637 82587,85461,356981
%N A194637 Record values in A194636.
%C A194637 The index sequence is 1, 3, 7, 24, 30, 55, 121, 168, 555, 687, 724, 7447, 26134, 28272, 324802, 419221, 4420051, 8467881, 50302257, 59186640, 135352084, 677738616, ... given by formula (A194639(n)+1)/2.
%D A194637 Wilfrid Keller, personal communication, 2010.
%H A194637 Chris K. Caldwell, The List of Largest Known Primes, <a href="https://t5k.org/primes/page.php?id=107">1355477231 * 2^356981 + 1</a>
%H A194637 Carlos Rivera, <a href="http://www.primepuzzles.net/problems/prob_030.htm">Problem 30</a>
%F A194637 a(n) = A194591(A194639(n)) = A194636((A194639(n)+1)/2).
%e A194637 A194636(55) = 6 since A194636(121) = 11 is the next record value.
%t A194637 l = -1; Flatten[Table[n = 2*n - 1; k = 0; While[! PrimeQ[n*2^k - 1] && ! PrimeQ[n*2^k + 1], k++]; If[k > l, l = k, {}], {n, 10^5}]] (* _Arkadiusz Wesolowski_, Sep 04 2011 *)
%Y A194637 Cf. A194591, A194600, A194603, A194606, A194607, A194608, A194635, A194636, A194638, A194639.
%Y A194637 Cf. A103963, A103964, A076335, A180247.
%K A194637 more,nonn
%O A194637 1,3
%A A194637 _Arkadiusz Wesolowski_, Aug 31 2011
%E A194637 a(22) was found in 2002 by Wilfrid Keller.