A088152 - OEIS

%I #13 Feb 16 2025 08:32:51

%S 1,0,0,0,0,0,0,0,1,2,1,1,1,6,6,5,0,0,4,4,6,1,3,3,1,4,5,4,0,5,0,3,0,3,

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

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

%N Value of n-th digit in octal representation of n^n.

%C a(n)=d(n) with n^n = Sum(d(k)*8^k: 0<=d(k)<8, k>=0).

%H Robert Israel, <a href="/A088152/b088152.txt">Table of n, a(n) for n = 0..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Octal.html">Octal</a>

%F a(n) = floor(n^n / 8^n) mod 8.

%e n=9, 9^9=387420489 -> '2705710511', '2---------': a(9)=2;

%e a(0)=1, a(k)=0 for 0<k<8 and a(8)=1.

%p f:= proc(n) local x,L;

%p    x:= n &^ n mod 8^(n+1);

%p    floor(x/8^n)

%p end proc:

%p f(0):= 1:

%p map(f, [$0..101]); # _Robert Israel_, Sep 19 2019

%o (Magma) [Floor(n^n/8^n) mod 8:n in [0..101]]; // _Marius A. Burtea_, Sep 20 2019

%Y Cf. A007094, A000312, A088150, A088151, A088153, A088154, A088155, A088156, A088157.

%K nonn,base,changed

%O 0,10

%A _Reinhard Zumkeller_, Sep 20 2003