%I #17 Sep 08 2022 08:45:56

%S 2,5,1,1,8,8,6,4,3,1,5,0,9,5,8,0,1,1,1,0,8,5,0,3,2,0,6,7,7,9,9,3,2,7,

%T 3,9,4,1,5,8,5,1,8,1,0,0,7,8,2,4,7,5,4,2,8,6,7,9,8,8,8,4,2,0,9,0,8,2,

%U 4,3,2,4,7,7,2,3,5,6,1,3,0,8,4,5,3,8,5,1,0,0,8,8,7,7,7,9,6,9,5,9,1,9,1,6,9

%N Decimal expansion of Pogson's ratio 100^(1/5).

%C Ratio appearing in the definition of the astronomical magnitude (brightness) scale.

%C Named after the English astronomer Norman Robert Pogson (1829-1891). - _Amiram Eldar_, Apr 24 2021

%H G. C. Greubel, <a href="/A189824/b189824.txt">Table of n, a(n) for n = 1..10000</a>

%H Norman Pogson, <a href="https://doi.org/10.1093/mnras/17.1.12">Magnitudes of Thirty-Six of the Minor Planets for the First Day of Each Month of the Year 1857</a>, Monthly Notices of the Royal Astronomical Society, Vol. 17, No. 1 (1856), pp. 12-15.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PogsonsRatio.html">Pogson's Ratio</a>.

%e 2.511886431509580111085032067799...

%t First[RealDigits[100^(1/5), 10, 200]]

%o (PARI) 10^.4 \\ _Charles R Greathouse IV_, Jan 15 2015

%o (Magma) 10^(2/5) // _G. C. Greubel_, Jan 14 2018

%K nonn,easy,cons

%O 1,1

%A _Eric W. Weisstein_, Apr 28 2011