A130917 a(n) is the sum of the digital roots of all of the previous terms.

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

Offset

1,3

Comments

Essentially identical to A007612, which is the main entry for this sequence. - N. J. A. Sloane, Aug 25 2007

Links

Table of n, a(n) for n=1..48.

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

Cf. A007612.

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