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 A065489 #19 Mar 15 2021 04:24:27
%S A065489 1,4,1,9,5,6,2,8,8,0,5,0,5,4,8,5,9,1,9,3,1,7,2,3,5,8,6,1,7,8,9,7,3,5,
%T A065489 3,5,9,1,6,6,0,7,1,5,8,6,3,0,5,1,2,2,5,4,2,6,9,8,9,8,3,6,9,5,5,6,4,3,
%U A065489 3,0,9,7,1,3,3,9,4,7,1,6,0,8,6,3,9,9,4,0,3,6,9,4,8,0,2,7,9,4,9
%N A065489 Decimal expansion of Product_{p prime} (1 + 1/(p^2+p-1)).
%H A065489 G. Niklasch, <a href="/A001692/a001692.html">Some number theoretical constants: 1000-digit values</a>. [Cached copy]
%F A065489 1 divided by A065463. - _R. J. Mathar_, Mar 26 2011
%e A065489 1.419562880505485919317235861789735359... = 1/0.704442200999....
%t A065489 $MaxExtraPrecision = 1200; digits = 99; terms = 1200; P[n_] := PrimeZetaP[n ]; LR = Join[{0, 0}, LinearRecurrence[{-2, 0, 1}, {2, -3, 6}, terms + 10]]; r[n_Integer] := LR[[n]]; Exp[NSum[r[n]*P[n-1]/(n-1), {n, 3, terms}, NSumTerms -> terms, WorkingPrecision -> digits+10]] // RealDigits[#, 10, digits]& // First (* _Jean-François Alcover_, Apr 18 2016 *)
%o A065489 (PARI) prodeulerrat(1 + 1/(p^2+p-1)) \\ _Amiram Eldar_, Mar 15 2021
%Y A065489 Cf. A065463, A078077.
%K A065489 cons,nonn
%O A065489 1,2
%A A065489 _N. J. A. Sloane_, Nov 19 2001