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A084860
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Expansion of (1-2x+2x^2-x^3)/(1-2x)^2.
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4
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1, 2, 6, 15, 36, 84, 192, 432, 960, 2112, 4608, 9984, 21504, 46080, 98304, 208896, 442368, 933888, 1966080, 4128768, 8650752, 18087936, 37748736, 78643200, 163577856, 339738624, 704643072, 1459617792, 3019898880, 6241124352
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Partial sums are A084858. Partial sums of A084860.
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FORMULA
| a(0)=1, a(n+1)=3*2^(n-2)(n+3)-0^n/4.
Equals binomial transform of nonzero terms of A026741: (1, 1, 3, 2, 5, 3, 7, 4,...). - Gary W. Adamson (qntmpkt(AT)yahoo.com), Apr 25 2008
Equals row sums of triangle A139633 - Gary W. Adamson (qntmpkt(AT)yahoo.com), Apr 27 2008
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MATHEMATICA
| CoefficientList[Series[(1-2x+2x^2-x^3)/(1-2x)^2, {x, 0, 50}], x] (* From Harvey P. Dale, Mar 30 2011 *)
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CROSSREFS
| Cf. A026741.
Cf. A139633.
Sequence in context: A153517 A136302 A116404 * A084798 A017923 A018018
Adjacent sequences: A084857 A084858 A084859 * A084861 A084862 A084863
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Jun 12 2003
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