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A085375
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a(n) = binomial(2*n+1, n+1)*binomial(n+4, 4).
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1
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1, 15, 150, 1225, 8820, 58212, 360360, 2123550, 12033450, 66050270, 353068716, 1845586470, 9464546000, 47738754000, 237329805600, 1164893795820, 5653161067950, 27157342385250, 129275302348500, 610315506350550, 2859764086899720, 13308425945529000
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n+1) = a(n)*2*(n+5)*(2*n+3)/((n+1)*(n+2)). - Chai Wah Wu, Jan 26 2016
G.f.: (1 - 3*x + 6*x^2 - 5*x^3) / (1 - 4*x)^(9/2). - Ilya Gutkovskiy, Nov 17 2021
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MAPLE
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seq(binomial(2*n+1, n+1)*binomial(n+4, 4), n=0..20); # Zerinvary Lajos, Jan 18 2007
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MATHEMATICA
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Table[Binomial[2*n + 1, n + 1] * Binomial[n + 4, 4], {n, 0, 30}]
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PROG
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(Python)
from __future__ import division
for n in range(501):
b = b*2*(n+5)*(2*n+3)//((n+1)*(n+2)) # Chai Wah Wu, Jan 26 2016
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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Mario Catalani (mario.catalani(AT)unito.it), Jun 26 2003
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STATUS
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approved
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