A225449 - OEIS

%I #30 Aug 08 2019 10:48:56

%S 1,7,8,2,5,0,2,0,6,4,6,2,8,9,1,4,7,0,8,9,4,4,3,5,3,9,4,9,6,3,5,2,5,7,

%T 2,3,9,4,9,4,8,8,1,0,0,4,8,4,1,4,8,5,4,9,9,2,2,7,1,9,2,2,2,5,1,6,3,7,

%U 2,2,0,0,8,9,5,2,9,0,9,6,9,4,8,8,8,2,4,3,6,6,7,9,8,8,2,0,4,3,9,0

%N Digits of the 10-adic integer (-9)^(1/7).

%C This is the 10's complement of A225446.

%H Seiichi Manyama, <a href="/A225449/b225449.txt">Table of n, a(n) for n = 0..10000</a>

%e       1^7 == -9 (mod 10).

%e      71^7 == -9 (mod 10^2).

%e     871^7 == -9 (mod 10^3).

%e    2871^7 == -9 (mod 10^4).

%e   52871^7 == -9 (mod 10^5).

%e   52871^7 == -9 (mod 10^6).

%o (PARI) n=0;for(i=1,100,m=(10^i-9);for(x=0,9,if(((n+(x*10^(i-1)))^7)%(10^i)==m,n=n+(x*10^(i-1));print1(x", ");break)))

%o (PARI) Vecrev(digits(truncate((-9+O(10^100))^(1/7)))) \\ _Seiichi Manyama_, Aug 04 2019

%o (PARI) N=100; Vecrev(digits(lift(chinese(Mod((-9+O(2^N))^(1/7), 2^N), Mod((-9+O(5^N))^(1/7), 5^N)))), N) \\ _Seiichi Manyama_, Aug 04 2019

%Y Digits of 10-adic integers:

%Y A225443 ((-1/9)^(1/7));

%Y A225446 (     9^(1/7));

%Y A225452 ( (1/9)^(1/7)).

%K nonn,base

%O 0,2

%A _Aswini Vaidyanathan_, May 11 2013