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Convolved Fibonacci numbers.
(Formerly M3899 N1600)
13

%I M3899 N1600 #61 May 15 2024 11:35:57

%S 1,5,20,65,190,511,1295,3130,7285,16435,36122,77645,163730,339535,

%T 693835,1399478,2790100,5504650,10758050,20845300,40075630,76495450,

%U 145052300,273381350,512347975,955187033,1772132390,3272875935,6018885570,11024814945,20118711993

%N Convolved Fibonacci numbers.

%C a(n) = (((-i)^n)/4!)*(d^4/dx^4)S(n+4,x)|_{x=i}, where i is the imaginary unit. Fourth derivative of Chebyshev S(n+4,x) polynomial evaluated at x=i multiplied by ((-i)^n)/4!. See A049310 for the S-polynomials. - _Wolfdieter Lang_, Apr 04 2007

%C a(n) = number of weak compositions of n in which exactly 4 parts are 0 and all other parts are either 1 or 2. - _Milan Janjic_, Jun 28 2010

%D J. Riordan, Combinatorial Identities, Wiley, 1968, p. 101.

%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H T. D. Noe, <a href="/A001873/b001873.txt">Table of n, a(n) for n = 0..500</a>

%H Peter J. Cameron, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL3/groups.html">Sequences realized by oligomorphic permutation groups</a>, J. Integ. Seqs. Vol. 3 (2000), #00.1.5.

%H Verner E. Hoggatt, Jr. and Marjorie Bicknell-Johnson, <a href="http://www.fq.math.ca/Scanned/15-2/hoggatt1.pdf">Fibonacci convolution sequences</a>, Fib. Quart., 15 (1977), 117-122.

%H Pieter Moree, <a href="https://arxiv.org/abs/math/0311205">Convoluted convolved Fibonacci numbers</a>, arXiv:math/0311205 [math.CO], 2003.

%H Mihai Prunescu and Lorenzo Sauras-Altuzarra, <a href="https://arxiv.org/abs/2405.04083">On the representation of C-recursive integer sequences by arithmetic terms</a>, arXiv:2405.04083 [math.LO], 2024. See p. 18.

%H Paul R. Stein and Michael S. Waterman, <a href="http://dx.doi.org/10.1016/0012-365X(79)90033-5">On some new sequences generalizing the Catalan and Motzkin numbers</a>, Discrete Math., 26 (1979), 261-272.

%H Paul R. Stein and Michael S. Waterman, <a href="/A001006/a001006_4.pdf">On some new sequences generalizing the Catalan and Motzkin numbers</a> [Corrected annotated scanned copy]

%H Michael S. Waterman, <a href="http://www.cmb.usc.edu/people/msw/Waterman.html">Home Page</a> (contains copies of his papers)

%H <a href="/index/Rec#order_10">Index entries for linear recurrences with constant coefficients</a>, signature (5,-5,-10,15,11,-15,-10,5,5,1).

%F G.f.: 1/(1-x-x^2)^5.

%F From _Wolfdieter Lang_, Nov 29 2002: (Start)

%F a(n) = Sum_{m=0.. floor(n/2)} binomial(4+n-m, 4)*binomial(n-m, m).

%F a(n) = ((1368 + 970*n + 215*n^2 + 15*n^3)*(n+1)*F(n+2) + 2*(408 + 305*n + 70*n^2 + 5*n^3)*(n+2)*F(n+1))/(4!*5^3), with F(n) = A000045(n). (End)

%F a(n) = F''''(n+4, 1)/24, i.e., 1/24 times the 4th derivative of the (n+4)th Fibonacci polynomial evaluated at 1. - _T. D. Noe_, Jan 18 2006

%F Recurrence: a(n) = 5*a(n-1) - 5*a(n-2) - 10*a(n-3) + 15*a(n-4) + 11*a(n-5) - 15*a(n-6) - 10*a(n-7) + 5*a(n-8) + 5*a(n-9) + a(n-10). - _Fung Lam_, May 11 2014

%F For n > 1, a(n) = (4/n+1)*a(n-1)+(8/n+1)*a(n-2). - _Tani Akinari_, Sep 14 2023

%p a:= n-> (Matrix(10, (i, j)-> `if`(i=j-1, 1, `if`(j=1, [5, -5, -10, 15, 11, -15, -10, 5, 5, 1][i], 0 )))^n)[1, 1]: seq(a(n), n=0..40); # _Alois P. Heinz_, Aug 15 2008

%t nn = 30; CoefficientList[Series[1/(1 - x - x^2)^5, {x, 0, nn}], x] (* _T. D. Noe_, Aug 10 2012 *)

%t LinearRecurrence[{5,-5,-10,15,11,-15,-10,5,5,1},{1,5,20,65,190,511,1295,3130,7285,16435},40] (* _Harvey P. Dale_, Aug 10 2021 *)

%o (Maxima) a[n]:=if n<2 then 4*n+1 else (4/n+1)*a[n-1]+(8/n+1)*a[n-2];

%o makelist(a[n],n,0,50); /* _Tani Akinari_, Sep 14 2023 */

%K nonn

%O 0,2

%A _N. J. A. Sloane_

%E More terms from _Wolfdieter Lang_, Nov 29 2002