OFFSET
1,1
COMMENTS
10's complement of A319739.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = 9 - A319739(n) for n >= 2.
EXAMPLE
3^3 == 7 == -1/7 (mod 10).
93^3 == 57 == -1/7 (mod 100).
593^3 == 857 == -1/7 (mod 1000).
5593^3 == 2857 == -1/7 (mod 10000).
...
...619383045593^3 = ...142857142857 = ...999999999999/7 = -1/7.
MAPLE
op([1, 3], padic:-rootp(7*x^3+1, 10, 100)); # Robert Israel, Mar 31 2019
PROG
(PARI) seq(n)={Vecrev(digits(lift(chinese( Mod((-1/7 + O(5^n))^(1/3), 5^n), Mod((-1/7 + O(2^n))^(1/3), 2^n)))), n)} \\ Following Andrew Howroyd's code for A319740.
CROSSREFS
10-adic cube root of p/q:
q=7: this sequence (p=-1), A319739 (p=1);
KEYWORD
nonn,base
AUTHOR
Jianing Song, Feb 23 2019
STATUS
approved