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 A084860 Expansion of (1-2x+2x^2-x^3)/(1-2x)^2. 4
 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; text; internal format)
 OFFSET 0,2 COMMENTS Partial sums are A084858. Partial sums of A084860. LINKS Index entries for linear recurrences with constant coefficients, signature (4,-4). 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, Apr 25 2008 Equals row sums of triangle A139633 - Gary W. Adamson, Apr 27 2008 MATHEMATICA CoefficientList[Series[(1-2x+2x^2-x^3)/(1-2x)^2, {x, 0, 50}], x]  (* Harvey P. Dale, Mar 30 2011 *) CROSSREFS Cf. A026741. Cf. A139633. Sequence in context: A136302 A116404 A301600 * A084798 A215149 A017923 Adjacent sequences:  A084857 A084858 A084859 * A084861 A084862 A084863 KEYWORD easy,nonn AUTHOR Paul Barry, Jun 12 2003 STATUS approved

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Last modified October 15 00:14 EDT 2019. Contains 328025 sequences. (Running on oeis4.)