A025771 - OEIS

%I #11 Sep 30 2023 12:15:34

%S 1,1,1,2,2,2,3,3,3,4,4,5,6,6,7,8,8,9,10,10,11,12,13,14,15,16,17,18,19,

%T 20,21,22,23,25,26,27,29,30,31,33,34,35,37,38,40,42,43,45,47,48,50,52,

%U 53,55,57,59,61,63,65,67

%N Expansion of 1/((1-x)(1-x^3)(1-x^11)).

%H <a href="/index/Rec#order_15">Index entries for linear recurrences with constant coefficients</a>, signature (1, 0, 1, -1, 0, 0, 0, 0, 0, 0, 1, -1, 0, -1, 1).

%F a(n)= +a(n-1) +a(n-3) -a(n-4) +a(n-11) -a(n-12) -a(n-14) +a(n-15). - _R. J. Mathar_, Aug 21 2014

%p A025771 := proc(n)

%p         round(n^2/66 +5*n/22 +68/99 + A099837(n+3)/9) ;

%p end proc: # _R. J. Mathar_, Aug 11 2012

%o (PARI) Vec(1/((1-x)*(1-x^3)*(1-x^11))+O(x^99)) \\ _Charles R Greathouse IV_, Sep 27 2012

%K nonn,easy

%O 0,4

%A _N. J. A. Sloane_.