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Search: id:A141478
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| 64, 256, 640, 1280, 2240, 3584, 5376, 7680, 10560, 14080, 18304, 23296, 29120, 35840, 43520, 52224, 62016, 72960, 85120, 98560, 113344, 129536, 147200, 166400, 187200, 209664, 233856, 259840, 287680, 317440, 349184, 382976, 418880, 456960
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OFFSET
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0,1
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COMMENT
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Number of n permutations (n>=3) of 5 objects u, v, z, x, y with repetition allowed, containing n-3 u's. Example:
if n=3 then n-3 =zero (0) u, a(1)=64
if n=4 then n-3= one (1) u, a(2)=256
if n=5 then n-3= two (2) u, a(3)=640
etc...
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FORMULA
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G.f.:64*x/(1-x)^4. a(n)=C(n+2,3)*4^3, n>=1.
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MAPLE
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seq(binomial(n+2, 3)*4^3, n=1..36);
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CROSSREFS
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Cf. A035008, A008586, A038231.
Sequence in context: A091077 A016994 A017066 this_sequence A107262 A045029 A029873
Adjacent sequences: A141475 A141476 A141477 this_sequence A141479 A141480 A141481
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KEYWORD
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nonn
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AUTHOR
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Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Aug 09 2008
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