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 A335004 #19 Oct 27 2024 09:23:47
%S A335004 1,0,8,2,7,6,2,1,9,3,2,6,0,9,2,4,5,8,0,1,2,2,1,8,8,0,3,8,1,9,0,9,2,6,
%T A335004 5,7,0,1,8,4,3,0,6,6,5,5,5,8,3,6,0,0,1,4,4,1,0,2,0,3,1,9,7,4,3,5,5,1,
%U A335004 2,8,6,1,9,2,9,8,2,9,5,0,4,3,4,2,4,2,2
%N A335004 Decimal expansion of 6*exp(gamma)/Pi^2.
%D A335004 Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 1.5.1, p. 31.
%D A335004 József Sándor, Dragoslav S. Mitrinovic, and Borislav Crstici, Handbook of Number Theory I, Springer Science & Business Media, 2005, chapter III, page 100.
%H A335004 J. Fabrykowski and M. V. Subbarao, <a href="https://doi.org/10.1515/9783110852790.201">The maximal order and the average order of multiplicative function sigma^(e)(n)</a>, in Jean M. de Koninck and Claude Levesque (eds.), Théorie des nombres/Number theory: Proceedings of the International Number Theory Conference held at Université Laval, July 5-18, 1987, Berlin, New York: de Gruyter, 1989, pp. 201-206.
%H A335004 Florian Luca and Carl Pomerance, <a href="http://doi.org/10.4064/cm92-1-10">On some problems of Mąkowski-Schinzel and Erdős concerning the arithmetical functions phi and sigma</a>, Colloquium Mathematicum, Vol. 92 (2002), pp. 111-130.
%H A335004 Michel Planat, <a href="http://arxiv.org/abs/1010.3239">Riemann hypothesis from the Dedekind psi function</a>, arXiv:1010.3239 [math.GM], 2010.
%F A335004 Equals limsup_{k->oo} esigma(k)/(k*log(log(k))), where esigma(k) is the sum of exponential divisors of k (A051377).
%F A335004 Equals A073004 * A059956 = A073004 / A013661 = 1 / A246499.
%F A335004 Equals lim_{k->oo} (1/log(k)) * Product_{p prime <= k} (1 + 1/p). - _Amiram Eldar_, Jul 09 2020
%e A335004 1.0827621932609245801221880381909265701843066555836...
%t A335004 RealDigits[6*Exp[EulerGamma]/Pi^2, 10, 100][[1]]
%o A335004 (PARI) 6*exp(Euler)/Pi^2 \\ _Michel Marcus_, May 19 2020
%Y A335004 Cf. A001620 (gamma), A013661 (Pi^2/6), A051377 (esigma), A059956 (6/Pi^2), A073004 (exp(gamma)), A246499 (Pi^2/(6*exp(gamma))).
%Y A335004 Cf. A236435, A236436.
%K A335004 nonn,cons
%O A335004 1,3
%A A335004 _Amiram Eldar_, May 19 2020