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a(n) = floor(n/16) + floor((n+1)/16) + floor((n+2)/16) + floor((n+3)/16).
4

%I #19 Sep 08 2022 08:45:13

%S 0,0,0,0,0,0,0,0,0,0,0,0,0,1,2,3,4,4,4,4,4,4,4,4,4,4,4,4,4,5,6,7,8,8,

%T 8,8,8,8,8,8,8,8,8,8,8,9,10,11,12,12,12,12,12,12,12,12,12,12,12,12,12,

%U 13,14,15,16,16,16,16,16,16,16,16,16,16,16,16,16,17,18,19,20,20,20,20

%N a(n) = floor(n/16) + floor((n+1)/16) + floor((n+2)/16) + floor((n+3)/16).

%H Reinhard Zumkeller, <a href="/A093391/b093391.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_14">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1,0,-1,2,-1,0,-1,2,-1,0,-1,2,-1).

%F From _R. J. Mathar_, Mar 22 2011: (Start)

%F a(n) = +2*a(n-1) -a(n-2) -a(n-4) +2*a(n-5) -a(n-6) -a(n-8) +2*a(n-9) -a(n-10) -a(n-12) +2*a(n-13) -a(n-14).

%F G.f.: x^13/ ( (1+x^4)*(x^8+1)*(x-1)^2 ).

%F (End)

%t Total/@(Floor/@(Partition[Range[0,90],4,1]/16)) (* _Harvey P. Dale_, Sep 21 2013 *)

%t CoefficientList[Series[x^13 / ((1 + x^4) (x^8 + 1) (x - 1)^2), {x, 0, 100}], x] (* _Vincenzo Librandi_, Feb 16 2018 *)

%o (Haskell)

%o a093391 n = sum $ map ((flip div 16) . (+ n)) [0..3] -- _Reinhard Zumkeller_, Oct 10 2013

%o (PARI) a(n) = n\16 + (n+1)\16 + (n+2)\16 + (n+3)\16 \\ _Andrew Howroyd_, Feb 15 2018

%o (Magma) [Floor(n/16)+Floor((n+1)/16)+Floor((n+2)/16)+Floor((n+3)/16): n in [0..100]]; // _Vincenzo Librandi_, Feb 16 2018

%Y Cf. A004524, A093390, A093392.

%Y Cf. A054900.

%K nonn

%O 0,15

%A _Reinhard Zumkeller_, Mar 28 2004