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 A070769 #30 Feb 16 2025 08:32:46 %S A070769 1,4,5,1,3,6,9,2,3,4,8,8,3,3,8,1,0,5,0,2,8,3,9,6,8,4,8,5,8,9,2,0,2,7, %T A070769 4,4,9,4,9,3,0,3,2,2,8,3,6,4,8,0,1,5,8,6,3,0,9,3,0,0,4,5,5,7,6,6,2,4, %U A070769 2,5,5,9,5,7,5,4,5,1,7,8,3,5,6,5,9,5,3,1,3,5,7,7,1,1,0,8,6,8,2,8,8,4 %N A070769 Decimal expansion of Soldner's constant. %C A070769 From _Amiram Eldar_, Aug 14 2020: (Start) %C A070769 The only positive solution to li(x) = 0, where li is the logarithmic integral. %C A070769 Named after the German physicist, mathematician and astronomer Johann Georg von Soldner (1776 - 1833). %C A070769 Also known as Ramanujan-Soldner constant. %C A070769 Mascheroni (1792) calculated the value 1.45137. Soldner (1809) calculated the value 1.4513692346. (End) %D A070769 Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003. See p. 425. %H A070769 Robert Price, <a href="/A070769/b070769.txt">Table of n, a(n) for n = 1..10000</a> %H A070769 Bruce C. Berndt and Ronald J. Evans, <a href="https://doi.org/10.1016/0377-0427(91)90104-R">Some elegant approximations and asymptotic formulas of Ramanujan</a>, Journal of computational and applied mathematics, Vol. 37 No. 1-3 (1991), pp. 35-41. See p. 38. %H A070769 Lorenzo Mascheroni, <a href="https://gutenberg.beic.it/webclient/DeliveryManager?pid=1365785&search_terms=DTL4">Adnotationes ad calculum integralem Euleri, In quibus nonnulla Problemata ab Eulero proposita resolvuntur, Pars altera</a>, Petrus Galeatius, Ticini 1792. See p. 17. %H A070769 Niels Nielsen, <a href="https://archive.org/details/diegammafunktion00niel">Die Gammafunktion</a>, New York : Chelsea, 1965. %H A070769 Johann Georg von Soldner, <a href="https://archive.org/details/bub_gb_g4Q_AAAAcAAJ/page/n49/mode/2up">Théorie et tables d'une nouvelle fonction transcendante</a>, München: Lindauer, 1809. See p. 42. %H A070769 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SoldnersConstant.html">Soldner's Constant</a>. %H A070769 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/LogarithmicIntegral.html">Logarithmic Integral</a>. %H A070769 Wikipedia, <a href="https://en.wikipedia.org/wiki/Logarithmic_integral_function">Logarithmic integral function</a>. %H A070769 Wikipedia, <a href="https://en.wikipedia.org/wiki/Ramanujan%E2%80%93Soldner_constant">Ramanujan-Soldner constant</a>. %H A070769 Marek Wolf, <a href="https://www.researchgate.net/publication/330413076_The_relations_between_Euler-Mascheroni_and_Ramanujan-Soldner_constants">The relations between Euler-Mascheroni and Ramanujan-Soldner constants</a>, 2019. %F A070769 Equals exp(A091723). - _Amiram Eldar_, Aug 14 2020 %e A070769 1.45136923488338105028396848589... %t A070769 RealDigits[ x /. FindRoot[ LogIntegral[x] == 0, {x, 2}, WorkingPrecision -> 105]][[1]] (* _Jean-François Alcover_, Nov 08 2012 *) %o A070769 (PARI) solve(x=1.4,2,real(eint1(-log(x)))) \\ _Charles R Greathouse IV_, Feb 23 2017 %Y A070769 Cf. A091723. %K A070769 nonn,cons %O A070769 1,2 %A A070769 _Eric W. Weisstein_, May 05 2002 %E A070769 Offset corrected and example added by _Stanislav Sykora_, May 18 2012