%I #22 Nov 15 2022 02:37:32
%S 0,1,2,2,3,3,3,4,4,4,4,5,5,5,5,5,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,7,7,
%T 8,8,8,8,8,8,8,8,8,8,8,8,8,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,0,0,0,0,0,
%U 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1
%N First digit after decimal point of 6th root of n.
%C When n is a sixth power, let a(n) = 0 rather than a(n) = 9. - _Charles R Greathouse IV_, Jan 06 2016
%H Vincenzo Librandi, <a href="/A023965/b023965.txt">Table of n, a(n) for n = 1..1000</a>
%t Array[ Function[ n, RealDigits[ N[ Power[ n, 1/6 ], 10 ], 10 ]// (#[ [ 1, #[ [ 2 ] ]+1 ] ])& ], 110 ]
%t Table[RealDigits[Surd[n,6],10,10][[1,2]],{n,120}] (* _Harvey P. Dale_, Jun 23 2016 *)
%o (PARI) a(n)=if(ispower(n,6), 0, 10*frac(sqrtn(n,6))\1) \\ _Charles R Greathouse IV_, Jan 06 2016
%o (Python)
%o from sympy import integer_nthroot
%o def A023965(n): return integer_nthroot(n*10**6,6)[0] % 10 # _Chai Wah Wu_, Nov 14 2022
%K nonn,base
%O 1,3
%A _N. J. A. Sloane_, _Olivier GĂ©rard_