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A212593
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a(n) is the difference between multiples of 9 with even and odd digit sum in base 8 in interval [0,8^n).
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4
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1, 8, 15, 232, 449, 7400, 14351, 237832, 461313, 7648968, 14836623, 246015528, 477194433, 7912700328, 15348206223, 254499628104, 493651049985, 8185582834056, 15877514618127, 263276481572712, 510675448527297, 8467876653984360
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OFFSET
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1,2
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LINKS
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FORMULA
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For n>=9, a(n) = 36*a(n-2)-126*a(n-4)+84*a(n-6)-9*a(n-8).
G.f.: x*(1+8*x-21*x^2-56*x^3+35*x^4+56*x^5-7*x^6-8*x^7)/((1-3*x^2)*(1-33*x^2+27*x^4-3*x^6)). [Bruno Berselli, May 22 2012]
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MATHEMATICA
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LinearRecurrence[{0, 36, 0, -126, 0, 84, 0, -9}, {1, 8, 15, 232, 449, 7400, 14351, 237832}, 22] (* Bruno Berselli, May 22 2012 *)
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CROSSREFS
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KEYWORD
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nonn,base,easy
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AUTHOR
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STATUS
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approved
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