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A180598
Digital root of 8n.
8
0, 8, 7, 6, 5, 4, 3, 2, 1, 9, 8, 7, 6, 5, 4, 3, 2, 1, 9, 8, 7, 6, 5, 4, 3, 2, 1, 9, 8, 7, 6, 5, 4, 3, 2, 1, 9, 8, 7, 6, 5, 4, 3, 2, 1, 9, 8, 7, 6, 5, 4, 3, 2, 1, 9, 8, 7, 6, 5, 4, 3, 2, 1, 9, 8, 7, 6, 5, 4, 3, 2, 1, 9, 8, 7, 6, 5, 4, 3, 2, 1, 9, 8, 7, 6, 5, 4, 3, 2, 1, 9, 8, 7, 6, 5, 4, 3, 2, 1, 9, 8, 7, 6, 5, 4
OFFSET
0,2
COMMENTS
Period of 9. - Robert G. Wilson v, Sep 20 2010
Essentially the same as A138531. - R. J. Mathar, Jul 09 2011
FORMULA
G.f.: -x*(9*x^8+x^7+2*x^6+3*x^5+4*x^4+5*x^3+6*x^2+7*x+8)/((x-1)*(x^2+x+1)*(x^6+x^3+1)). - Colin Barker, Aug 19 2012
MATHEMATICA
f[n_] := Mod[8 n - 1, 9] + 1; f[0] = 0; Array[f, 105, 0] (* Robert G. Wilson v, Sep 20 2010 *)
CROSSREFS
KEYWORD
easy,nonn,base
AUTHOR
Odimar Fabeny, Sep 10 2010
EXTENSIONS
More terms from Robert G. Wilson v, Sep 20 2010
STATUS
approved