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 A374831 #10 Jul 21 2024 08:46:16
%S A374831 4,5,8,9,3,7,4,9,8,5,0,5,4,3,5,9,6,1,3,0,6,3,4,2,6,1,8,1,0,0,1,8,9,3,
%T A374831 8,5,6,7,2,0,0,8,1,6,3,7,4,5,2,8,9,8,1,2,3,4,2,8,7,5,7,7,7,7,3,1,7,5,
%U A374831 4,5,6,6,1,2,2,5,4,3,0,8,5,8,9,2,2,8,6,2,5,4,3,2,0,9,3,5,8,0,7,8,2,5,7,2,9
%N A374831 Decimal expansion of Product_{p prime} (1 - (1/(p*(p - 1)))*p^2/(p^2 + 1)).
%H A374831 Rafael Jakimczuk, <a href="https://www.researchgate.net/publication/382207808_Numbers_of_the_form_p-1_where_p_is_prime">Numbers of the form p-1 where p is prime</a>, July 2024. See p. 23.
%e A374831 0.4589374985054359613063426181...
%o A374831 (PARI) prodeulerrat(1-p^2/(p*(p-1)*(p^2+1)))
%Y A374831 Cf. A005596, A005597, A065414, A065418, A065419, A374830 (lower bound).
%K A374831 nonn,cons
%O A374831 0,1
%A A374831 _Stefano Spezia_, Jul 21 2024