%I M4470
%S 1,8,3,6,1,5,2,6,7,3
%N Decimal expansion of protontoelectron mass ratio.
%C Curiously, this ratio coincides with 6*Pi^5 = 1836.1181... up to 5 digits (first noticed in 1952 by Friedrich Lenz in the Physical Review).  _JeanFrançois Alcover_, Jul 27 2016
%D John Barrow, The Constants of Nature, 367pp, Jonathan Cape, 2002.
%D K. R. Lang, Astrophysical Data: Planets and Stars, SpringerVerlag, NY, 1991.
%D Martin J. Rees. Just Six Numbers: the deep forces that shape the universe. Phoenix. 1999
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H E. R. Cohen and B. N. Taylor, <a href="http://physics.nist.gov/cuu/Archive/1986RMP.pdf">The 1986 adjustment of the fundamental physical constants</a>, Rev. Modern Phys., 59 (1987), 11211148.
%H Friedrich Lenz, <a href="https://doi.org/10.1103/PhysRev.82.554.2">The Ratio of Proton and Electron Masses</a>, Phys. Rev. 82, 554  Published 15 May 1951.
%H NIST, <a href="http://physics.nist.gov/cgibin/cuu/Value?mpsme">protonelectron mass ratio</a>
%e 1836.15...
%Y Cf. A003677.
%K cons,nonn,nice,hard
%O 4,2
%A _N. J. A. Sloane_.
%E Updated by _Ivan Panchenko_, May 29 2019
