OFFSET
0,2
COMMENTS
x = ...301322,
x^2 = ...114234,
x^3 = ...000003 = 3.
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..1431
Wikipedia, Hensel's Lemma.
FORMULA
a(0) = 0 and a(1) = 2, a(n) = a(n-1) + 2 * (a(n-1)^3 - 3) mod 5^n for n > 1.
EXAMPLE
a(1) = ( 2)_5 = 2,
a(2) = ( 22)_5 = 12,
a(3) = ( 322)_5 = 87,
a(4) = (1322)_5 = 212.
PROG
(PARI) a(n)=truncate((3+O(5^n))^(1/3)); \\ Joerg Arndt, Aug 06 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Aug 06 2017
STATUS
approved