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A093834
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Expansion of (1-2x)^2/((1-3x)(1-4x)).
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1
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1, 3, 13, 55, 229, 943, 3853, 15655, 63349, 255583, 1028893, 4135255, 16600069, 66577423, 266841133, 1068958855, 4280618389, 17136822463, 68590336573, 274490486455, 1098349366309, 4394559726703, 17581725691213, 70337363118055
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Binomial transform of A093833.
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FORMULA
| a(n)=4^n-3^n/3-0^n/3. a(n+1)=4^(n+1)-3^n, n>0.
a(0)=1, a(1)=3, a(2)=13, a(n)=7*a(n-1)-12*a(n-2) [From Harvey P. Dale, Dec 27 2011]
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MATHEMATICA
| CoefficientList[Series[(1-2x)^2/((1-3x)(1-4x)), {x, 0, 30}], x] (* or *) Join[{1}, LinearRecurrence[{7, -12}, {3, 13}, 30]] (* From Harvey P. Dale, Dec 27 2011 *)
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CROSSREFS
| Cf. A085350.
Sequence in context: A037779 A140320 A037583 * A033887 A183804 A117376
Adjacent sequences: A093831 A093832 A093833 * A093835 A093836 A093837
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Apr 17 2004
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