%I #19 Dec 25 2019 16:30:16
%S 6,9,2,15,14,1,3,3,9,62,118,227,452,889,1764,3527,7051,14099,28189,
%T 56316,112514,224801,449150,897411,1793058,3582589,7158127,14302155,
%U 28576121,57095926,114079338,227933875,455418600,909939789,1818086520,3632590451
%N "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.
%H Colin Barker, <a href="/A129938/b129938.txt">Table of n, a(n) for n = 1..1000</a>
%H <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,1,1,1,1,1,1,1).
%F 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
%p 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
%t 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 *)
%o (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
%Y Cf. A129939.
%K base,easy,nonn,word
%O 1,1
%A _Eric Angelini_, Jun 09 2007
%E Corrected and extended by _R. J. Mathar_, Sep 02 2007