OFFSET
1,2
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
1^9 == 1 (mod 10).
91^9 == 11 (mod 100).
391^9 == 111 (mod 1000).
4391^9 == 1111 (mod 10000).
84391^9 == 11111 (mod 100000).
584391^9 == 111111 (mod 1000000).
MAPLE
A[1]:= 1: P:= 1:
for d from 2 to 100 do
R:= (expand((10^(d-1)*x+P)^9 - ((10^d-1)/9)) mod 10^d)/10^(d-1);
A[d]:= subs(msolve(R, 10), x);
P:= subs(10^(d-1)*A[d]+P);
od:
seq(A[i], i=1..100); # Robert Israel, Oct 03 2018
PROG
(PARI) n=0; for(i=1, 100, m=(10^i-1)/9; for(x=0, 9, if(((n+(x*10^(i-1)))^9)%(10^i)==m, n=n+(x*10^(i-1)); print1(x", "); break)))
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Aswini Vaidyanathan, May 11 2013
STATUS
approved