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A104476
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a(n) = binomial(n+7,7)*binomial(n+11,7).
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1
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330, 6336, 61776, 411840, 2123550, 9060480, 33372768, 109219968, 324246780, 886828800, 2261413440, 5427392256, 12352970916, 26829982080, 55895796000, 112183843200, 217706770710, 409800980160, 750266946000, 1339149240000, 2335141487250, 3985308138240
(list;
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refs;
listen;
history;
text;
internal format)
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OFFSET
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0,1
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LINKS
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Index entries for linear recurrences with constant coefficients, signature (15,-105,455,-1365,3003,-5005,6435,-6435,5005,-3003,1365,-455,105,-15,1).
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FORMULA
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Sum_{n>=0} 1/a(n) = 539*Pi^2 - 114905813/21600.
Sum_{n>=0} (-1)^n/a(n) = 1741019/7200 - 49*Pi^2/2. (End)
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EXAMPLE
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a(0): C(0+7,7)*C(0+11,7) = C(7,7)*C(11,7) = 1*330 = 330;
a(7): C(7+7,7)*C(7+11,7) = C(14,7)*C(18,7) = 3432*31824 = 109219968.
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MATHEMATICA
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f[n_] := Binomial[n + 7, 7]*Binomial[n + 11, 7]; Table[ f[n], {n, 0, 19}] (* Robert G. Wilson v, Apr 20 2005 *)
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PROG
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(PARI) vector(30, n, n--; binomial(n+7, 7)*binomial(n+11, 7)) \\ Michel Marcus, Jul 31 2015
(Magma) [Binomial(n+7, 7)*Binomial(n+11, 7): n in [0..30]]; // Vincenzo Librandi, Jul 31 2015
(Python)
A104476_list, m = [], [3432, -1716, 660, 330, 330, 330, 330, 330, 330, 330, 330, 330, 330, 330, 330]
for _ in range(10**2):
for i in range(14):
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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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EXTENSIONS
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STATUS
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approved
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