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A108499
Number of values of k (1<=k<=n) where k^(n+1) = k mod n, or equivalently where sum_i{1<=i<=n} k^i = 0 mod n.
5
1, 2, 2, 3, 2, 6, 2, 5, 4, 6, 2, 9, 2, 6, 4, 9, 2, 14, 2, 15, 8, 6, 2, 15, 6, 6, 10, 9, 2, 18, 2, 17, 4, 6, 4, 21, 2, 6, 8, 25, 2, 42, 2, 9, 8, 6, 2, 27, 8, 22, 4, 15, 2, 38, 12, 15, 8, 6, 2, 45, 2, 6, 16, 33, 4, 18, 2, 15, 4, 18, 2, 35, 2, 6, 12, 9, 4, 42, 2, 45, 28, 6, 2, 63, 4, 6, 4, 15, 2, 42, 4
OFFSET
1,2
FORMULA
a(n)=n-A108500(n). a(n)=n iff n is in A014117.
EXAMPLE
a(2)=2 since 1^3 = 1 mod 2 and 2^3 = 8 = 0 mod 2 = 2 mod 2.
a(3)=2 since 1^1+1^2+1^3 = 3 = 0 mod 3 and 3^1+3^2+3^3 = 39 = 0 mod 3 but 2^1+2^2+2^3 = 14 = 2 mod 3 != 0 mod 3.
CROSSREFS
Numbers of zeros in rows of A108497 or A108498.
Sequence in context: A376567 A068903 A329607 * A260895 A107753 A197929
KEYWORD
nonn
AUTHOR
Henry Bottomley, Jun 06 2005
STATUS
approved