OFFSET
0,2
LINKS
Robert Israel, Table of n, a(n) for n = 0..1182
FORMULA
a(0) = 0 and a(1) = 4, a(n) = a(n-1) + (a(n-1)^5 - 2) mod 7^n for n > 1.
EXAMPLE
a(1) = ( 4)_7 = 4,
a(2) = ( 64)_7 = 46,
a(3) = ( 164)_7 = 95,
a(4) = (3164)_7 = 1124.
MAPLE
A:= op([1, 3], padic:-rootp(x^5 -2, 7, 25)):
seq(add(A[i]*10^(i-1), i=1..n), n=0..25); # Robert Israel, Aug 04 2019
PROG
(PARI) {a(n) = truncate((2+O(7^n))^(1/5))}
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Aug 03 2019
STATUS
approved