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A163771 Triangle interpolating the swinging factorial (A056040) restricted to even indices with its binomial inverse. Same as interpolating the central trinomial coefficients (A002426) with the central binomial coefficients (A000984). 4
1, 1, 2, 3, 4, 6, 7, 10, 14, 20, 19, 26, 36, 50, 70, 51, 70, 96, 132, 182, 252, 141, 192, 262, 358, 490, 672, 924, 393, 534, 726, 988, 1346, 1836, 2508, 3432, 1107, 1500, 2034, 2760, 3748, 5094, 6930, 9438, 12870 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,3

COMMENTS

Triangle read by rows. For n >= 0, k >= 0 let

T(n,k) = sum{i=k..n} (-1)^(n-i)*binomial(n-k,n-i)*(2i)$

where i$ denotes the swinging factorial of i (A056040).

REFERENCES

Peter Luschny, "Divide, swing and conquer the factorial and the lcm{1,2,...,n}", preprint, April 2008.

LINKS

M. Z. Spivey and L. L. Steil, , The k-Binomial Transforms and the Hankel Transform, J. Integ. Seqs. Vol. 9 (2006), #06.1.1.

Peter Luschny, Swinging Factorial.

EXAMPLE

1

1, 2

3, 4, 6

7, 10, 14, 20

19, 26, 36, 50, 70

51, 70, 96, 132, 182, 252

141, 192, 262, 358, 490, 672, 924

MAPLE

For the functions 'DiffTria' and 'swing' see A163770. Computes n rows of the triangle.

a := n -> DiffTria(k->swing(2*k), n, true);

CROSSREFS

Sum rows are A163774. Cf. A056040, A163650, A163771, A163772, A002426, A000984.

Sequence in context: A035941 A039854 A032480 * A194855 A117851 A050679

Adjacent sequences:  A163768 A163769 A163770 * A163772 A163773 A163774

KEYWORD

nonn,tabl

AUTHOR

Peter Luschny (peter(AT)luschny.de), Aug 05 2009

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Last modified February 13 06:53 EST 2012. Contains 205451 sequences.