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a(n) = 8*a(n-1) - 21*a(n-2) + 20*a(n-3) - 5*a(n-4), with initial terms a(0)=1, a(1)=7, a(2)=35, a(3)=154.
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%I #56 May 05 2023 10:30:55

%S 1,7,35,154,632,2487,9529,35875,133471,492538,1807268,6604891,

%T 24069905,87539199,317907067,1153307002,4180842064,15147734815,

%U 54860799881,198634274203,719047882103,2602540622106,9418700937340,34084040705539,123335178991777,446277892754167,1614771692630099

%N a(n) = 8*a(n-1) - 21*a(n-2) + 20*a(n-3) - 5*a(n-4), with initial terms a(0)=1, a(1)=7, a(2)=35, a(3)=154.

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (8,-21,20,-5).

%F G.f.: ( 1-x+x^3 ) / ( (5*x^2-5*x+1)*(x^2-3*x+1) ). - _R. J. Mathar_, May 05 2023

%Y Extension of patterns illustrated in A001519, A033191, A033190, A094667, A030191, A094788.

%K nonn,easy

%O 0,2

%A _Peter Morris_, Dec 20 2020

%E Offset corrected by _Jon E. Schoenfield_, Feb 05 2021