This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A136695 #8 Nov 29 2024 17:36:30 %S A136695 1,1,2,6,3,7,2,6,6,6,4,4,6,6,4,4,3,3,6,2,5,1,6,2,6,6,4,4,6,6,4,4,6,6, %T A136695 4,4,2,2,4,4,4,4,1,3,4,4,3,5,6,6,4,4,2,2,4,4,4,4,3,1,4,4,5,3,3,3,6,2, %U A136695 1,5,6,2,2,2,4,4,2,2,4,4,5,5,2,6,3,7,2,6,2,2,4,4,2,2,4,4,6,6,4,4 %N A136695 Final nonzero digit of n! in base 8. %H A136695 Robert Israel, <a href="/A136695/b136695.txt">Table of n, a(n) for n = 0..10000</a> %F A136695 From _Robert Israel_, Sep 26 2018: (Start) %F A136695 If A011371(n) == 0 (mod 3) then a(n) = A049606(n) mod 8. %F A136695 If A011371(n) == 1 (mod 3) then a(n) = 2*(A049606(n) mod 4). %F A136695 If A011371(n) == 2 (mod 3) then a(n) = 4. (End) %e A136695 6! = 720 decimal = 1320 octal, so a(6) = 2. %p A136695 P:= 1: E:= 0: a[0]:= 1: %p A136695 for n from 1 to 100 do %p A136695 v:= padic:-ordp(n,2); %p A136695 P:= P*(n/2^v) mod 8; %p A136695 E:= E + v; %p A136695 if E mod 3 = 0 then a[n]:= P %p A136695 elif E mod 3 = 1 then a[n]:= 2*(P mod 4) %p A136695 else a[n]:= 4 %p A136695 fi %p A136695 od: %p A136695 seq(a[n],n=0..100); # _Robert Israel_, Sep 26 2018 %t A136695 Table[IntegerDigits[FromDigits[Reverse[IntegerDigits[n!,8]]]][[1]],{n,0,100}] (* _Harvey P. Dale_, Nov 29 2024 *) %Y A136695 Cf. A000142, A136690, A136691, A136692, A136693, A136694, A136696, A008904, A136697, A136698, A136699, A136700, A136701, A136702. %Y A136695 Cf. A011371, A049606. %K A136695 base,easy,nonn %O A136695 0,3 %A A136695 _Carl R. White_, Jan 16 2008