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a(n) = A110654(A110654(n)).
4

%I #13 May 30 2016 00:27:15

%S 0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,6,6,6,6,7,7,7,7,8,8,8,8,9,

%T 9,9,9,10,10,10,10,11,11,11,11,12,12,12,12,13,13,13,13,14,14,14,14,15,

%U 15,15,15,16,16,16,16,17,17,17,17,18,18,18,18,19,19,19,19,20,20,20,20,21

%N a(n) = A110654(A110654(n)).

%C a(n) = A008621(n+1) = A002265(n+3).

%C A110656(n) = A110654(a(n)) = a(A110654(n)).

%H G. C. Greubel, <a href="/A110655/b110655.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,1,-1).

%F a(n) = ceiling(n/4).

%F From _Chai Wah Wu_, May 29 2016: (Start)

%F a(n) = a(n-1) + a(n-4) - a(n-5) for n>4.

%F G.f.: x/(x^5 - x^4 - x + 1). (End)

%p A110655:=n->ceil(n/4): seq(A110655(n), n=0..100); # _Wesley Ivan Hurt_, May 29 2016

%t CoefficientList[Series[x/(x^5 - x^4 - x + 1), {x, 0, 100}], x] (* _Wesley Ivan Hurt_, May 29 2016 *)

%t LinearRecurrence[{1, 0, 0, 1, -1}, {0, 1, 1, 1, 1}, 50] (* _G. C. Greubel_, May 29 2016 *)

%Y Cf. A002265, A008621, A110654, A110656, A110657.

%K nonn,easy

%O 0,6

%A _Reinhard Zumkeller_, Aug 05 2005