Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #10 May 21 2023 15:04:02
%S 1,1,1,1,1,1,1,2,3,4,4,4,4,4,5,6,8,9,10,10,10,11,12,14,16,18,19,20,21,
%T 22,24,26,29,31,33,35,37,39,41,44,47,50,53,56,59,62,65,68,72,76,80,84,
%U 88,92,96,100,105,110,115
%N Expansion of 1/((1-x)(1-x^7)(1-x^8)(1-x^9)).
%H <a href="/index/Rec#order_25">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,0,0,0,1,0,0,-1,0,0,0,0,-1,0,0,1,0,0,0,0,0,1,-1).
%F G.f.: 1/((1-x)*(1-x^7)*(1-x^8)*(1-x^9)).
%F a(n) = a(n-1) + a(n-7) - a(n-10) - a(n-15) + a(n-18) + a(n-24) - a(n-25). - _Wesley Ivan Hurt_, Mar 07 2022
%t CoefficientList[Series[1/((1-x)(1-x^7)(1-x^8)(1-x^9)),{x,0,60}],x] (* or *) LinearRecurrence[ {1,0,0,0,0,0,1,0,0,-1,0,0,0,0,-1,0,0,1,0,0,0,0,0,1,-1},{1,1,1,1,1,1,1,2,3,4,4,4,4,4,5,6,8,9,10,10,10,11,12,14,16},60] (* _Harvey P. Dale_, May 21 2023 *)
%o (PARI) Vec(1/((1-x)*(1-x^7)*(1-x^8)*(1-x^9)) + O(x^99)) \\ _Jinyuan Wang_, Mar 18 2020
%K nonn,easy
%O 0,8
%A _N. J. A. Sloane_