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 A187431 #38 Aug 02 2020 02:24:49 %S A187431 30131199,50817201,56496039,74316929,171407609,276672151,293315671, %T A187431 337876949,356498179,359830101,372590921,432448789,501182201, %U A187431 541961069,577016839,616411051,749536461,776113741,903321909,919203811,1005047121,1285328811,1323139751,1340738371 %N A187431 Numbers n that generate 5 primes under the first 5 iterations of the map n->A002731(n). %C A187431 Numbers n such that m=(n^2+1)/2, p=(m^2+1)/2, q=(p^2+1)/2, r=(q^2+1)/2 and s=(r^2+1)/2 are all prime. %C A187431 Subsequence of A188547 which itself is subsequence of A188546 which is subsequence of A116945. %C A187431 a(1)=30131199=A188547(70). %C A187431 Two numbers n that generate 6 primes... are a(23)=1323139751 and a(78)=10185588801. %H A187431 Charles R Greathouse IV, <a href="/A187431/b187431.txt">Table of n, a(n) for n = 1..405</a>, replacing an earlier b-file from Zak Seidov %H A187431 Stephan Baier, <a href="https://doi.org/10.1006/jnth.2002.2811">On the Bateman-Horn conjecture</a>, Journal of Number Theory 96, 432-448 (2002). %H A187431 Paul T. Bateman, Roger A. Horn, <a href="http://dx.doi.org/10.1090/S0025-5718-1962-0148632-7">A heuristic asymptotic formula concerning the distribution of prime numbers</a>, Math. Comp. 16 (1962) 363-367. %Y A187431 Cf. A002731, A105318, A116945, A188546, A188547. %K A187431 nonn %O A187431 1,1 %A A187431 _Zak Seidov_, Apr 05 2011