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A130917
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a(n) is the sum of the digital roots of all of the previous terms.
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0
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1, 1, 2, 4, 8, 16, 23, 28, 29, 31, 35, 43, 50, 55, 56, 58, 62, 70, 77, 82, 83, 85, 89, 97, 104, 109, 110, 112, 116, 124, 131, 136, 137, 139, 143, 151, 158, 163, 164, 166, 170, 178, 185, 190, 191, 193, 197, 205
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OFFSET
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1,3
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COMMENTS
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LINKS
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FORMULA
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G.f.: x*(5*x^5+x^4+2*x^3+x^2-x+1) / ((x-1)^2*(x+1)*(x^2-x+1)). - Colin Barker, Jan 17 2014
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EXAMPLE
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a(8) = 28 because the digital roots of the previous terms are 1,1,2,4,8,7 and 5 and 1+1+2+4+8+7+5 = 28
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PROG
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(PARI) Vec(x*(5*x^5+x^4+2*x^3+x^2-x+1)/((x-1)^2*(x+1)*(x^2-x+1)) + O(x^100)) \\ Colin Barker, Jan 17 2014
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CROSSREFS
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KEYWORD
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easy,nonn,base
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AUTHOR
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Stephen Casey (hexomino(AT)gmail.com), Aug 23 2007
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STATUS
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approved
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