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A026056 a(n) = (d(n)-r(n))/5, where d = A026054 and r is the periodic sequence with fundamental period (3,3,0,0,4).

%I A026056 #12 Oct 21 2022 21:28:46
%S A026056 2,5,10,16,23,33,45,60,77,96,119,145,175,208,244,285,330,380,434,492,
%T A026056 556,625,700,780,865,957,1055,1160,1271,1388,1513,1645,1785,1932,2086,
%U A026056 2249,2420,2600,2788,2984,3190,3405,3630,3864,4107,4361,4625,4900,5185,5480,5787,6105,6435,6776,7128,7493
%N A026056 a(n) = (d(n)-r(n))/5, where d = A026054 and r is the periodic sequence with fundamental period (3,3,0,0,4).
%H A026056 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1,0,1,-3,3,-1).
%F A026056 a(n) = (n + 2)*(n + 3)*(n + 13)/30 - 1/5*(2 + (1/2 + 7/10*5^(1/2))*cos(2*n*Pi/5) + ( - 1/10*2^(1/2)*(5 + 5^(1/2))^(1/2))*sin(2*n*Pi/5) + (1/2 - 7/10*5^(1/2))*cos(4*n*Pi/5) + ( - 1/10*2^(1/2)*(5 - 5^(1/2))^(1/2))*sin(4*n*Pi/5)). - _Richard Choulet_, Dec 14 2008
%F A026056 G.f.: x^3*( 2-x+x^2-x^3 ) / ( (x^4+x^3+x^2+x+1)*(x-1)^4 ). - _R. J. Mathar_, Jun 22 2013
%F A026056 a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) + a(n-5) - 3*a(n-6) + 3*a(n-7) - a(n-8). - _Wesley Ivan Hurt_, Jul 29 2022
%Y A026056 Cf. A152893, A026054.
%K A026056 nonn,easy
%O A026056 3,1
%A A026056 _Clark Kimberling_