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A124820
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Expansion of (1-x)/(1-4x+3x^2-x^3).
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5
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1, 3, 9, 28, 88, 277, 872, 2745, 8641, 27201, 85626, 269542, 848491, 2670964, 8407925, 26467299, 83316385, 262271568, 825604416, 2598919345, 8181135700, 25753389181, 81069068969, 255197244033, 803335158406, 2528817970494
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Row sums of A124819.
Contribution from Gary W. Adamson (qntmpkt(AT)yahoo.com), Jul 27 2010: (Start)
Let M = a triangle with the triangular series in every column, but the
leftmost column is shifted upwards one row. Then A124820 = Lim_{n->inf} M^n,
the left-shifted vector considered as a sequence. (End)
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FORMULA
| a(n)=sum{k=0..n, C(n+2k+1,3k+1)}
a(n)=A052529(n+1)-A052529(n), n>1. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Dec 15 2008]
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CROSSREFS
| Sequence in context: A115239 A118365 A095716 * A022020 A170953 A199104
Adjacent sequences: A124817 A124818 A124819 * A124821 A124822 A124823
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Nov 08 2006
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