A014318 Convolution of Catalan numbers and powers of 2.
1, 3, 8, 21, 56, 154, 440, 1309, 4048, 12958, 42712, 144210, 496432, 1735764, 6145968, 21986781, 79331232, 288307254, 1054253208, 3875769606, 14315659632, 53097586284, 197677736208, 738415086066
Offset: 0
Keywords
Links
- Fung Lam, Table of n, a(n) for n = 0..1600
- W. Chammam, F. Marcellán and R. Sfaxi, Orthogonal polynomials, Catalan numbers, and a general Hankel determinant evaluation, Linear Algebra and its Applications, Volume 436, Issue 7, 1 April 2012, Pages 2105-2116.
Programs
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Magma
A014318:= func< n | (&+[2^(n-j)*Catalan(j): j in [0..n]]) >; [A014318(n): n in [0..40]]; // G. C. Greubel, Jan 09 2023
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Maple
a:=proc(n) options operator, arrow: sum(2^(n-j)*binomial(2*j,j)/(j+1), j=0..n) end proc: seq(a(n), n=0..23); # Emeric Deutsch, Oct 16 2008
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Mathematica
a[n_]:= a[n]= Sum[2^(n-j)*CatalanNumber[j], {j,0,n}]; Table[a[n], {n,0,40}] (* G. C. Greubel, Jan 09 2023 *)
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SageMath
def A014318(n): return sum(2^(n-j)*catalan_number(j) for j in range(n+1)) [A014318(n) for n in range(41)] # G. C. Greubel, Jan 09 2023
Formula
From Emeric Deutsch, Oct 16 2008: (Start)
G.f.: (1-sqrt(1-4*z))/(2*z*(1-2*z)).
a(n) = Sum_{j=0..n} (2^(n-j) * binomial(2*j,j)/(j+1)). (End)
Recurrence: (n+1)*a(n) = 32*(2*n-7)*a(n-5) + 48*(8-3*n)*a(n-4) + 8*(16*n-29)*a(n-3) + 4*(13-14*n)*a(n-2) + 12*n*a(n-1), n>=5. - Fung Lam, Mar 09 2014
Asymptotics: a(n) ~ 2^(2n+1)/n^(3/2)/sqrt(Pi). - Fung Lam, Mar 21 2014
G.f. A(x) satisfies: A(x) = 1 / (1 - 2*x) + x * (1 - 2*x) * A(x)^2. - Ilya Gutkovskiy, Nov 21 2021
Comments