A010780 - OEIS

%I #17 Aug 01 2020 11:35:37

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

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

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

%N Decimal expansion of 18th root of 2.

%H Vincenzo Librandi, <a href="/A010780/b010780.txt">Table of n, a(n) for n = 1..5000</a>

%F Equals Product_{k>=0} (1 + (-1)^k/(18*k + 17)). - _Amiram Eldar_, Aug 01 2020

%t RealDigits[Power[2, (18)^-1],10,120][[1]] (* _Harvey P. Dale_, Jul 14 2011 *)

%o (PARI) sqrtn(2,18) \\ _Charles R Greathouse IV_, Apr 15 2014

%K nonn,cons

%O 1,3

%A _N. J. A. Sloane_.