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 A086127 #20 Jul 14 2025 10:03:18
%S A086127 4889,18059,62639,225527,557093,604973,700703,804077,806903,837077,
%T A086127 1341203,1363403,1932197,2004269,2062703,2284637,2797463,3157379,
%U A086127 3493103,3746399,3995687,4155413,4227893,4493297,5534939,5708603
%N A086127 Numbers k such that k remains prime after five iteration of function f(j) = 14*f(j)+1, starting at f(1) = prime.
%C A086127 {p, 14p+1, 196p+15, 2744p+211, 38416p+2955, 537824p+41371} are all primes, where p is prime.
%e A086127 First chain is: {4889,68447,958259,13415627,187818779,2629462907}.
%e A086127 10th chain is {837077,11719079,164067107,2296939499,32157152987,450200141819}.
%t A086127 k=0; m=14; Do[s=Prime[n]; s1=m*s+1; s2=m*s1+1; s3=m*s2+1; s4=m*s3+1; s5=m*s4+1; If[PrimeQ[s]&&PrimeQ[s1]&&PrimeQ[s2]&&PrimeQ[s3]&&PrimeQ[s4]&&PrimeQ[s5], k=k+1; Print[s]], {n, 1, 1000000}]
%t A086127 Select[Range[6000000],And@@PrimeQ[NestList[14#+1&,#,5]]&] (* _Harvey P. Dale_, Sep 17 2012 *)
%Y A086127 Cf. A085956, A086361, A086362, A023330, A059766, A023287, A000668, A076481.
%K A086127 nonn
%O A086127 1,1
%A A086127 _Labos Elemer_, Jul 23 2003