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 A098567 #8 Jul 23 2021 05:24:23
%S A098567 2,3,3,5,5,5,7,7,31,5,59,5,11,137,397,211,2851,601,373,271,17467,127,
%T A098567 1657,52951,6547,11971,37489
%N A098567 Smallest prime p such that p# + Mersenne-prime(n) is prime.
%t A098567 f[p_] := Module[{k = 2, q = 2}, While[!PrimeQ[k + p], q = NextPrime[q]; k *= q]; q]; f /@ (2^MersennePrimeExponent[Range[10]] - 1) (* _Amiram Eldar_, Jul 23 2021 *)
%Y A098567 Cf. A000043, A000668, A002110, A098566.
%K A098567 nonn,more
%O A098567 1,1
%A A098567 _Pierre CAMI_, Sep 15 2004
%E A098567 a(21)-a(27) from _Amiram Eldar_, Jul 23 2021