cp's OEIS Frontend

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.

A345288 Decimal expansion of Product_{p primes} sqrt(1 + 1/(4*p*(p-1))).

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%I A345288 #10 Jun 14 2021 02:32:27
%S A345288 1,0,9,6,9,8,3,1,1,9,1,1,4,3,5,7,1,5,0,9,2,5,1,4,8,0,4,9,3,7,5,0,9,6,
%T A345288 6,6,4,9,3,6,2,1,1,6,7,6,0,5,4,3,6,7,2,8,7,7,6,5,4,3,4,5,2,9,8,6,9,4,
%U A345288 6,3,6,6,6,6,6,0,3,1,8,2,1,6,7,7,0,9,7,0,7,3,2,2,6,3,4,6,7,2,5,6,6,8,6,5,5
%N A345288 Decimal expansion of Product_{p primes} sqrt(1 + 1/(4*p*(p-1))).
%H A345288 Steven R. Finch, <a href="https://doi.org/10.1017/9781316997741">Mathematical Constants II</a>, Encyclopedia of Mathematics and Its Applications, Cambridge University Press, Cambridge, 2018, p. 50.
%F A345288 Equals sqrt(Pi) * lim_{n->infinity} sqrt(log(n))/n * Sum_{k=1..n} 1/A034444(k).
%e A345288 1.09698311911435715092514804937509666493621167605436728776543452986946366666...
%t A345288 $MaxExtraPrecision = 1000; Clear[f]; f[p_] := Sqrt[1 + 1/(4*p*(p-1))]; Do[cc = Rest[CoefficientList[Series[Log[f[1/x]], {x, 0, m}], x, m + 1]]; Print[f[2] * Exp[N[Sum[Indexed[cc, n] * (PrimeZetaP[n] - 1/2^n), {n, 2, m}], 110]]], {m, 100, 500, 100}]
%o A345288 (PARI) sqrt(prodeulerrat(1 + 1/(4*p*(p-1)))) \\ _Amiram Eldar_, Jun 13 2021
%Y A345288 Cf. A034444, A083281, A345231.
%K A345288 nonn,cons
%O A345288 1,3
%A A345288 _Vaclav Kotesovec_, Jun 13 2021