A083859 Main diagonal of generalized Fibonacci array A083856.
0, 1, 1, 4, 9, 41, 133, 673, 2737, 15130, 72181, 430739, 2320825, 14815529, 88005541, 596681296, 3843559137, 27515587661, 189933449365, 1428716457761, 10474213334761, 82448447397646, 637534807917701, 5233087759204967, 42445677865505425, 362213650380301201
Offset: 0
Links
- G. C. Greubel, Table of n, a(n) for n = 0..690
Programs
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GAP
Concatenation([0], List([1..30], n-> Sum([0..Int((n-1)/2)], j-> Binomial(n-j-1, j)*n^j) )); # G. C. Greubel, Dec 27 2019
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Magma
[0] cat [ &+[Binomial(n-j-1, j)*n^j: j in [0..Floor((n-1)/2)]] : n in [1..30]]; // G. C. Greubel, Dec 27 2019
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Maple
seq( `if`(n=0, 0, simplify( (-sqrt(n)*I)^(n-1)*ChebyshevU(n-1, I/(2*sqrt(n)))) ), n=0..30); # G. C. Greubel, Dec 27 2019 # second Maple program: a:= n-> (<<0|1>,
>^n)[1, 2]: seq(a(n), n=0..25); # Alois P. Heinz, Oct 19 2021 -
Mathematica
Table[DifferenceRoot[Function[{y, m}, {y[2 + m] == y[1 + m] + n*y[m], y[0] == 0, y[1] == 1}]][n], {n, 0, 20}] (* Benedict W. J. Irwin, Nov 03 2016 *) Table[If[n==0, 0, Round[(Sqrt[n])^(n-1)*Fibonacci[n, 1/Sqrt[n]] ]], {n,0,30}] (* G. C. Greubel, Dec 27 2019 *)
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PARI
vector(31, n, if(n==1, 0, round((-sqrt(n-1)*I)^(n-2)*polchebyshev(n-2, 2, I/(2*sqrt(n-1)))) ) ) \\ G. C. Greubel, Dec 27 2019
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Sage
[0]+[(-sqrt(n)*I)^(n-1)*chebyshev_U(n-1, I/(2*sqrt(n))) for n in (1..30)] # G. C. Greubel, Dec 27 2019
Formula
a(n) = (((1 + sqrt(4*n + 1))/2)^n - ((1 - sqrt(4*n + 1))/2)^n)/sqrt(4*n + 1).
a(n) = A193376(n-1,n) for n >= 2. - R. J. Mathar, Aug 23 2011
a(n) = y(n,n), where y(m+2,n) = y(m+1,n) + n*y(m,n) with y(0,n) = 0 and y(1,n) = 1 for all n. - Benedict W. J. Irwin, Nov 03 2016
a(n) = [x^n] x/(1 - x - n*x^2). - Ilya Gutkovskiy, Oct 10 2017
a(n) = Sum_{s = 0..floor((n-1)/2)} binomial(n-1-s, s) * n^s. - Petros Hadjicostas, Dec 24 2019
From G. C. Greubel, Dec 27 2019: (Start)
a(n) = (sqrt(n))^n * Fibonacci(n, 1/sqrt(n)), with a(0)=0.
a(n) = (-sqrt(n)*i)^(n-1)*ChebyshevU(n-1, i/(2*sqrt(n))), with a(0)=0. (End)
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