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A218127
Number of 10-ary sequences with primitive period n.
2
1, 10, 90, 990, 9900, 99990, 998910, 9999990, 99990000, 999999000, 9999899910, 99999999990, 999998990100, 9999999999990, 99999989999910, 999999999899010, 9999999900000000, 99999999999999990, 999999998999001000, 9999999999999999990, 99999999989999990100
OFFSET
0,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..1000 (terms 0..300 from Alois P. Heinz)
FORMULA
a(n) = Sum_{d|n} 10^d * mu(n/d) for n>0, a(0) = 1.
G.f.: 1 + 10 * Sum_{k>=1} mu(k) * x^k / (1 - 10*x^k). - Ilya Gutkovskiy, Apr 15 2021
MAPLE
with(numtheory):
a:= n-> `if`(n=0, 1, add(10^d*mobius(n/d), d=divisors(n))):
seq(a(n), n=0..30);
CROSSREFS
Column k=10 of A143324.
Sequence in context: A097394 A172199 A063945 * A322647 A243106 A046706
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Oct 21 2012
STATUS
approved