A010782 - OEIS

%I #21 Dec 27 2021 21:48:01

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

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

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

%N Decimal expansion of 20th root of 2.

%H Vincenzo Librandi, <a href="/A010782/b010782.txt">Table of n, a(n) for n = 1..5000</a>

%F Equals Product_{k>=0} (1 + (-1)^k/(20*k + 19)). - _Amiram Eldar_, Aug 01 2020

%t RealDigits[N[2^(1/20), 100]][[1]] (* _Vladimir Joseph Stephan Orlovsky_, Jan 25 2012 *)

%t RealDigits[Surd[2,20],10,120][[1]] (* _Harvey P. Dale_, Feb 06 2020 *)

%o (PARI) sqrtn(2,20) \\ _Charles R Greathouse IV_, Apr 15 2014

%K nonn,cons

%O 1,3

%A _N. J. A. Sloane_