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A122852
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Row sums of number triangle A122851.
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2
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1, 1, 2, 3, 6, 11, 24, 51, 122, 291, 756, 1979, 5526, 15627, 46496, 140451, 442194, 1414931, 4687212, 15785451, 54764846, 193129659, 698978136, 2570480147, 9672977706
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| Essentially the same as A072374. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jun 18 2008
Diagonal sums of A008279. [From Paul Barry (pbarry(AT)wit.ie), Feb 11 2009]
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FORMULA
| a(n)=sum{k=0..n, C(k,n-k)*(n-k)!}.
Contribution from Paul Barry (pbarry(AT)wit.ie), Feb 11 2009: (Start)
G.f.: 1/(1-x-x^2/(1-x^2/(1-x-2x^2/(1-2x^2/(1-x-3x^2/(1-3x^2/(1-x-4x^2/(1-4x^2/(1-... (continued fraction).
a(n)=sum{k=0..floor(n/2), C(n-k,k)k!}. (End)
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CROSSREFS
| Sequence in context: A036648 A047750 A072187 * A072374 A192573 A107113
Adjacent sequences: A122849 A122850 A122851 * A122853 A122854 A122855
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Sep 14 2006
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