A023968 - OEIS

%I #15 Apr 02 2018 15:36:54

%S 0,0,1,1,1,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,

%T 4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,

%U 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6

%N First digit after decimal point of 9th root of n.

%H Vincenzo Librandi, <a href="/A023968/b023968.txt">Table of n, a(n) for n = 1..1000</a>

%t Array[ Function[ n, RealDigits[ N[ Power[ n, 1/9 ], 10 ], 10 ]// (#[ [ 1, #[ [ 2 ] ]+1 ] ])& ], 110 ]

%t Table[Mod[Floor[10*Surd[n,9]],10],{n,120}] (* _Harvey P. Dale_, Apr 02 2018 *)

%K nonn,base

%O 1,6

%A _N. J. A. Sloane_, _Olivier Gérard_