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A094388
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Expansion of (1-2x-x^2)/((1-x)(1-3x)).
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2
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1, 2, 4, 10, 28, 82, 244, 730, 2188, 6562, 19684, 59050, 177148, 531442, 1594324, 4782970, 14348908, 43046722, 129140164, 387420490, 1162261468, 3486784402, 10460353204, 31381059610, 94143178828, 282429536482, 847288609444
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Binomial transform of 0^n+A001045(n).
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..600
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FORMULA
| a(n)=3^n/3-0^n/3+1; a(n+1)/2=A007051(n); a(n+1)-1=3^n.
a(n)=A034472(n-1), n>0. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 05 2008]
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MATHEMATICA
| CoefficientList[Series[(1-2x-x^2)/((1-x)(1-3x)), {x, 0, 30}], x] (* From Harvey P. Dale, May 20 2011 *)
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PROG
| (MAGMA) [3^n/3-0^n/3+1: n in [0..30]]; // Vincenzo Librandi, May 21 2011
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CROSSREFS
| Sequence in context: A149821 A149822 A034472 * A187256 A148110 A149823
Adjacent sequences: A094385 A094386 A094387 * A094389 A094390 A094391
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Apr 28 2004
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