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 A086124 #12 May 31 2025 20:13:35
%S A086124 5,191,8831183,559832762721564181,
%T A086124 3655022053493602810873312808337814473758207442937
%N A086124 Primes generated by linear recursion: f(n) = prime(n) * f(n-1) + 2, f(1) = 1.
%C A086124 f(n) = 1, 5, 27, 191, 2103, 27341, 464799, 8831183, 203117211, ... .
%C A086124 a(6) has 298 decimal digits.
%F A086124 a(n) = f(A086125(n)).
%t A086124 f[x_] := Prime[x]*f[x-1]+2; f[1]=1; Do[s=f[n]; If[PrimeQ[s], Print[n]], {n, 1, 1000}]
%Y A086124 Cf. A000668, A076481, A086122, A086123, A086125.
%K A086124 nonn
%O A086124 1,1
%A A086124 _Labos Elemer_, Jul 23 2003