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 A122583 a(n) = a(n - 1) - 2*a(n - 2) + a(n - 3) + 3*(-2*a(n - 4) + a(n - 5)). 1

%I

%S 1,1,1,1,1,-3,-7,-3,5,25,45,-3,-107,-191,-175,253,1045,1189,-171,

%T -3547,-7527,-4603,11497,33945,40869,-10487,-141071,-248407,-120131,

%U 421141,1227961,1332777,-726439,-5051271,-8369959,-3306635,16738977,43110597,41391949,-33360335,-183387403,-283721435

%N a(n) = a(n - 1) - 2*a(n - 2) + a(n - 3) + 3*(-2*a(n - 4) + a(n - 5)).

%C This recursion is inspired by Ulam's early experiments in derivative recursions.

%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (1,-2,1,-6,3).

%F G.f.:(-1-7*x^4-x^3-2*x^2)*x/(-1+3*x^5-6*x^4+x^3-2*x^2+x). - Maksym Voznyy (voznyy(AT)mail.ru), Aug 11 2009

%p A122583 := proc(n) option remember ; if n <= 5 then 1; else A122583(n-1)-2*A122583(n-2)+A122583(n-3)+3*(-2*A122583(n-4)+A122583(n-5)) ; fi ; end: seq(A122583(n),n=1..80) ; # _R. J. Mathar_, Sep 18 2007

%t a[0] = 1; a[1] = 1; a[2] = 1; a[3] = 1; a[4] = 1; a[n_] := a[n] = a[n - 1] - 2*a[n - 2] + a[n - 3] + 3*(-2*a[n - 4] + a[n - 5]); Table[a[n], {n, 0, 30}]

%K sign

%O 1,6

%A _Roger L. Bagula_, Sep 19 2006

%E Edited by _N. J. A. Sloane_, Oct 01 2006

%E More terms from _R. J. Mathar_, Sep 18 2007

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Last modified September 26 20:34 EDT 2021. Contains 347672 sequences. (Running on oeis4.)