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 A109602 #6 Nov 01 2019 16:30:11
%S A109602 1,4,5,6,7,8,9,19,20,29,31,97,113,181,286,419,485,670,1216
%N A109602 Numbers n such that n!/(pi(n)!*2^n)+1 is prime.
%C A109602 Next term, if it exists, is > 3000. - _Ray Chandler_, Aug 04 2005
%t A109602 f[n_] := n!/Fold[Times, 1, Range[PrimePi[n]]]*2^n + 1; Do[ If[ PrimeQ[ f[n]], Print[n]], {n, 1000}]
%Y A109602 Cf. A108894.
%K A109602 nonn
%O A109602 1,2
%A A109602 _Robert G. Wilson v_, Jul 18 2005
%E A109602 a(19)=1216 from _Ray Chandler_, Aug 04 2005