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A122522 a(n) = a(n - 2) + a(n - 8), with a(1) = ... = a(8) = 1.

%I A122522 #20 Oct 25 2024 09:33:25
%S A122522 1,1,1,1,1,1,1,1,2,2,3,3,4,4,5,5,7,7,10,10,14,14,19,19,26,26,36,36,50,
%T A122522 50,69,69,95,95,131,131,181,181,250,250,345,345,476,476,657,657,907,
%U A122522 907,1252,1252,1728,1728,2385,2385,3292,3292,4544,4544,6272,6272,8657,8657
%N A122522 a(n) = a(n - 2) + a(n - 8), with a(1) = ... = a(8) = 1.
%H A122522 G. C. Greubel, <a href="/A122522/b122522.txt">Table of n, a(n) for n = 1..2500</a>
%H A122522 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (0,1,0,0,0,0,0,1).
%F A122522 G.f.: x*(1+x)/(1 - x^2 - x^8). - _G. C. Greubel_, May 01 2017
%t A122522 Rest@CoefficientList[Series[x*(1+x)/(1-x^2-x^8), {x,0,70}], x] (* _G. C. Greubel_, May 01 2017 *)
%o A122522 (PARI) my(x='x+O('x^70)); Vec(x*(1+x)/(1-x^2-x^8)) \\ _G. C. Greubel_, May 01 2017
%o A122522 (Magma) [n le 8 select 1 else Self(n-2) +Self(n-8): n in [1..70]]; // _G. C. Greubel_, Oct 24 2024
%o A122522 (SageMath)
%o A122522 @CachedFunction # a = A122522
%o A122522 def a(n): return 1 if n<9 else a(n-2) + a(n-8)
%o A122522 [a(n) for n in range(1,71)] # _G. C. Greubel_, Oct 24 2024
%Y A122522 Cf. A003269.
%K A122522 nonn,easy,less
%O A122522 1,9
%A A122522 _Roger L. Bagula_, Sep 16 2006
%E A122522 Edited by _N. J. A. Sloane_, Sep 17 2006