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 A130917 a(n) is the sum of the digital roots of all of the previous terms. 0
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Essentially identical to A007612, which is the main entry for this sequence. - N. J. A. Sloane, Aug 25 2007 LINKS Index entries for linear recurrences with constant coefficients, signature (2,-1,-1,2,-1). FORMULA 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 EXAMPLE 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 PROG (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 CROSSREFS Sequence in context: A257165 A262224 A058961 * A007612 A112395 A004207 Adjacent sequences:  A130914 A130915 A130916 * A130918 A130919 A130920 KEYWORD easy,nonn,base AUTHOR Stephen Casey (hexomino(AT)gmail.com), Aug 23 2007 STATUS approved

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Last modified January 22 20:40 EST 2019. Contains 319365 sequences. (Running on oeis4.)