%I #19 Feb 28 2023 02:15:33
%S 0,0,1,1,2,2,2,2,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,
%T 5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
%U 6,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
%N First digit after decimal point of 8th root of n.
%H Vincenzo Librandi, <a href="/A023967/b023967.txt">Table of n, a(n) for n = 1..1000</a>
%t Array[ Function[ n, RealDigits[ N[ Power[ n, 1/8 ], 10 ], 10 ]// (#[ [ 1, #[ [ 2 ] ]+1 ] ])& ], 110 ]
%t Table[Mod[Floor[10N[Surd[n,8]]],10],{n,130}] (* _Harvey P. Dale_, Apr 11 2020 *)
%o (Python)
%o from sympy import integer_nthroot
%o def A023967(n): return integer_nthroot(n*10**8,8)[0]%10 # _Chai Wah Wu_, Feb 27 2023
%K nonn,base
%O 1,5
%A _N. J. A. Sloane_, _Olivier GĂ©rard_