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A108500
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.
1
0, 0, 1, 1, 3, 0, 5, 3, 5, 4, 9, 3, 11, 8, 11, 7, 15, 4, 17, 5, 13, 16, 21, 9, 19, 20, 17, 19, 27, 12, 29, 15, 29, 28, 31, 15, 35, 32, 31, 15, 39, 0, 41, 35, 37, 40, 45, 21, 41, 28, 47, 37, 51, 16, 43, 41, 49, 52, 57, 15, 59, 56, 47, 31, 61, 48, 65, 53, 65, 52, 69, 37, 71, 68, 63, 67
OFFSET
1,5
FORMULA
a(n)=n-A108499(n). a(n)=0 iff n is in A014117. a(p)=p-2 for p prime.
EXAMPLE
a(2)=0 since 1^3 = 1 mod 2 and 2^3 = 8 = 0 mod 2 = 2 mod 2.
a(3)=1 since 2^1+2^2+2^3 = 14 = 2 mod 3 != 0 mod 3 but 1^1+1^2+1^3 = 3 = 0 mod 3 and 3^1+3^2+3^3 = 39 = 0 mod 3.
CROSSREFS
Numbers of nonzeros in rows of A108497 or A108498.
Sequence in context: A088191 A179179 A291503 * A322937 A326989 A326937
KEYWORD
nonn
AUTHOR
Henry Bottomley, Jun 06 2005
STATUS
approved