A129938 "Self-Fibonacci"; a(n) is the sum of the last nine terms. Sequence starts with 6,9,2,15,14,1,3,3,9 which are f,i,b,o,n,a,c,c,i if you consider a=1, b=2, c=3, ..., z=26.

6, 9, 2, 15, 14, 1, 3, 3, 9, 62, 118, 227, 452, 889, 1764, 3527, 7051, 14099, 28189, 56316, 112514, 224801, 449150, 897411, 1793058, 3582589, 7158127, 14302155, 28576121, 57095926, 114079338, 227933875, 455418600, 909939789, 1818086520, 3632590451

Offset

1,1

Links

Colin Barker, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (1,1,1,1,1,1,1,1,1).

Formula

G.f.: x*(6+3*x-13*x^2-2*x^3-18*x^4-45*x^5-44*x^6-47*x^7-44*x^8) / (1-x-x^2-x^3-x^4-x^5-x^6-x^7-x^8-x^9). - Colin Barker, Mar 11 2016

Maple

A129938 := proc(n) option remember ; if n <= 9 then op(n, [6, 9, 2, 15, 14, 1, 3, 3, 9]) ; else add(A129938(n-i), i=1..9) fi ; end: seq(A129938(n), n=1..50) ; # R. J. Mathar, Sep 02 2007

Mathematica

LinearRecurrence[{1, 1, 1, 1, 1, 1, 1, 1, 1}, {6, 9, 2, 15, 14, 1, 3, 3, 9}, 40] (* or *) LinearRecurrence[{1, 1, 1, 1, 1, 1, 1, 1, 1}, LetterNumber[ "fibonacci"], 40] (* Harvey P. Dale, Dec 25 2019 *)

Prog

(PARI) Vec(x*(6+3*x-13*x^2-2*x^3-18*x^4-45*x^5-44*x^6-47*x^7-44*x^8) / (1-x-x^2-x^3-x^4-x^5-x^6-x^7-x^8-x^9) + O(x^50)) \\ Colin Barker, Mar 11 2016

Crossrefs

Cf. A129939.

Sequence in context: A188618 A225125 A181852 * A022698 A013707 A002162

Adjacent sequences: A129935 A129936 A129937 * A129939 A129940 A129941

Keyword

base,easy,nonn,word

Author

Eric Angelini, Jun 09 2007

Extensions

Corrected and extended by R. J. Mathar, Sep 02 2007

Status

approved