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 A348830 #36 Mar 22 2025 07:02:14
%S A348830 7,13,703,14527,524354,3546333857,6785975897,30837755428255,
%T A348830 26315372006162602624,261082967559450339374,5060595675665117852243,
%U A348830 39265825923549359199986975497,123256266165246897346935034271,2125193947328394509208261354339475,7291398849693213195350018936947639700634973,2135676603454582708484868425511295057240283
%N A348830 Denominator of relativistic sum w(2n) of the velocities v = 1/p^(2n) over all primes p, in units where the speed of light c = 1.
%F A348830 a(n) = Denominator(tanh(Sum_{p prime} arctanh(1/p^(2n)))).
%F A348830 a(n) = Denominator((zeta(2n)^2-zeta(4n))/(zeta(2n)^2+zeta(4n))).
%F A348830 a(n) = Denominator((1-t(2n))/(1+t(2n))), where t(2n) = A114362(n)/A114363(n).
%e A348830 w(2) = 3/7, w(4) = 1/13, w(6) = 12/703, ...
%t A348830 r[s_] := Zeta[2*s]/Zeta[s]^2; w[s_] := (1 - r[s])/(1 + r[s]); Table[Denominator[w[2*n]], {n, 1, 15}] (* _Amiram Eldar_, Nov 01 2021 *)
%Y A348830 The numerators are A348829.
%Y A348830 Cf. A114362, A114363.
%K A348830 nonn,frac
%O A348830 1,1
%A A348830 _Thomas Ordowski_, Nov 01 2021
%E A348830 More terms from _Amiram Eldar_, Nov 01 2021