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A119694 a(n) = Fibonacci(n) * Catalan(n). 3

%I #23 Apr 12 2024 06:13:11

%S 0,1,2,10,42,210,1056,5577,30030,165308,923780,5231954,29953728,

%T 173095700,1008263880,5913855450,34898020290,207042729630,

%U 1234218400800,7388927397390,44406274641300,267807758800920,1620247684628040,9831059348368050,59810275503119232

%N a(n) = Fibonacci(n) * Catalan(n).

%H Alois P. Heinz, <a href="/A119694/b119694.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n) = A000045(n) * A000108(n). - _Alois P. Heinz_, Aug 12 2017

%F Sum_{n>=0} a(n)/8^n = 4 - 6*sqrt(2/5). - _Amiram Eldar_, May 04 2023

%F G.f.: (1-sqrt((20*x+4*sqrt(-16*x^2-4*x+1)-12*x+6)/10))/(2*x). - _Vladimir Kruchinin_, Apr 12 2024

%p seq(combinat[fibonacci](n)*(binomial(2*n, n)/(n+1)), n=0..27);

%p # second Maple program:

%p a:= proc(n) option remember; `if`(n<2, n,

%p ((2*n-1)*(2*n*a(n-1)+(8*n-12)*a(n-2)))/(n*(n+1)))

%p end:

%p seq(a(n), n=0..25); # _Alois P. Heinz_, Aug 12 2017

%t Table[Fibonacci[n]CatalanNumber[n],{n,0,30}] (* _Harvey P. Dale_, Aug 27 2017 *)

%Y Cf. A000045, A000108, A000984.

%K easy,nonn,changed

%O 0,3

%A _Zerinvary Lajos_, Jun 09 2006

%E Name edited by _Alois P. Heinz_, Aug 12 2017

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Last modified April 24 06:24 EDT 2024. Contains 371918 sequences. (Running on oeis4.)