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A163844
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Row sums of triangle A163841.
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1
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1, 5, 25, 125, 621, 3065, 15051, 73645, 359485, 1752125, 8532591, 41537105, 202200415, 984526275, 4795673085, 23372376525, 113978687085, 556205251325, 2716129289775
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| a(n) = sum{k=0..n} sum{i=k..n} binomial(n-k,n-i)*(2i)$
where i$ denotes the swinging factorial of i (A056040).
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LINKS
| Peter Luschny, Swinging Factorial.
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MAPLE
| swing := proc(n) option remember; if n = 0 then 1 elif
irem(n, 2) = 1 then swing(n-1)*n else 4*swing(n-1)/n fi end:
a := proc(n) local i, k; add(add(binomial(n-k, n-i)*swing(2*i), i=k..n), k=0..n) end:
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CROSSREFS
| Cf. A163841.
Sequence in context: A061974 A015950 A126642 * A057831 A014946 A188580
Adjacent sequences: A163841 A163842 A163843 * A163845 A163846 A163847
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KEYWORD
| nonn
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AUTHOR
| Peter Luschny (peter(AT)luschny.de), Aug 06 2009
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